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Kleybolte ME, Vagin SI, Rieger B. A Polymer Lost in the Shuffle: The Perspective of Poly(para)phenylenes. MACROMOL CHEM PHYS 2023. [DOI: 10.1002/macp.202200441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Moritz E. Kleybolte
- WACKER‐Chair of Macromolecular Chemistry Catalysis Research Center Technical University of Munich Lichtenbergstr. 4 85748 Garching Germany
| | - Sergei I. Vagin
- WACKER‐Chair of Macromolecular Chemistry Catalysis Research Center Technical University of Munich Lichtenbergstr. 4 85748 Garching Germany
| | - Bernhard Rieger
- WACKER‐Chair of Macromolecular Chemistry Catalysis Research Center Technical University of Munich Lichtenbergstr. 4 85748 Garching Germany
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2
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Radford CL, Kelly TL. Controlling solid-state structure and film morphology in non-fullerene organic photovoltaic devices. CAN J CHEM 2021. [DOI: 10.1139/cjc-2021-0134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Organic solar cells (OSCs) have long promised to provide renewable energy in a scalable, cost-effective way; however, for years, their relatively low efficiency has been a significant barrier to commercialization. Recent progress on cell efficiency means that OSCs are now much more competitive with other established technologies. These key advancements have come from better understanding and controlling the molecular structure, solid-state packing, and film morphology of the light absorbing layer. This focused review will explore the different ways that the solid-state structure and film morphology of the light absorbing layer can be controlled. It will examine the key features of an efficient light absorbing layer and present guiding principles for creating efficient OSCs. The future directions and remaining research questions of this field will be briefly discussed.
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Affiliation(s)
- Chase L. Radford
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, Canada
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, Canada
| | - Timothy L. Kelly
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, Canada
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, Canada
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3
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Abdiulrsool H. AL-Taher, Lafy F. AL-Badry, Semiromi EH. Improvement of the Optoelectronic Properties of Terazulene Molecules for Organic Solar Cell Applications. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2021. [DOI: 10.1134/s1990793121090025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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4
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Cohen AE, Jackson NE, de Pablo JJ. Anisotropic Coarse-Grained Model for Conjugated Polymers: Investigations into Solution Morphologies. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00302] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander E. Cohen
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Nicholas E. Jackson
- Department of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - Juan J. de Pablo
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
- Center for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
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5
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Madrid-Úsuga D, Reina JH. Molecular Structure, Quantum Coherence, and Solvent Effects on the Ultrafast Electron Transport in BODIPY- C60 Derivatives. J Phys Chem A 2021; 125:2518-2531. [PMID: 33754739 DOI: 10.1021/acs.jpca.1c00603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photoinduced electron transfer in multichromophore molecular systems is defined by a critical interplay between their core unit configuration (donor, molecular bridge, and acceptor) and their system-solvent coupling; these lead to energy and charge transport processes that are key in the design of molecular antennas for efficient light harvesting and organic photovoltaics. Here, we quantify the ultrafast non-Markovian dissipative dynamics of electron transfer in D-π-A molecular photosystems comprising 1,3,5,7-tetramethyl-8-phenyl-4,4-difluoroboradiazaindacene (BODIPY), Zn-porphyrin, fulleropyrrolidine, and fulleroisoxazoline. We find that the stabilization energy of the charge transfer states exhibits a significant variation for different polar (methanol, tetrahydrofuran (THF)) and nonpolar (toluene) environments and determine such sensitivity according to the molecular structure and the electron-vibration couplings that arise at room temperature. For the considered donor-acceptor (D-A) dyads, we show that the stronger the molecule-solvent coupling, the larger the electron transfer rates, regardless of the dyads' electronic coherence properties. We find such coupling strengths to be the largest (lowest) for methanol (toluene), with an electron transfer rate difference of 2 orders of magnitude between the polar and nonpolar solvents. For the considered donor-bridge-acceptor (D-B-A) triads, the molecular bridge introduces an intermediate state that allows the realization of Λ or cascaded-type energy mechanisms. We show that the latter configuration, obtained for BDP-ZnP-[PyrC60] in methanol, exhibits the highest transfer rate of all of the computed triads. Remarkably, and in contrast with the dyads, we show that the larger charge transfer rates are obtained for triads that exhibit prolonged electron coherence and population oscillations.
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Affiliation(s)
- Duvalier Madrid-Úsuga
- Centre for Bioinformatics and Photonics-CIBioFi, Universidad del Valle, Calle 13 No. 100-00, Edificio E20 No. 1069, 760032 Cali, Colombia.,Departamento de Física, Universidad del Valle, 760032 Cali, Colombia
| | - John H Reina
- Centre for Bioinformatics and Photonics-CIBioFi, Universidad del Valle, Calle 13 No. 100-00, Edificio E20 No. 1069, 760032 Cali, Colombia.,Departamento de Física, Universidad del Valle, 760032 Cali, Colombia
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6
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Wang T, Brédas JL. Organic Photovoltaics: Understanding the Preaggregation of Polymer Donors in Solution and Its Morphological Impact. J Am Chem Soc 2021; 143:1822-1835. [DOI: 10.1021/jacs.0c09542] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Tonghui Wang
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721-0088, United States
| | - Jean-Luc Brédas
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721-0088, United States
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7
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Munshi J, Chien T, Chen W, Balasubramanian G. Elasto-morphology of P3HT:PCBM bulk heterojunction organic solar cells. SOFT MATTER 2020; 16:6743-6751. [PMID: 32588009 DOI: 10.1039/d0sm00849d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Predicting the mechanical properties of organic semiconductors is important when using these materials in flexible electronics applications. For instance, knowledge of the mechanical and thermal stability of thin film organic solar cells (OSCs) is critical for the roll-to-roll production of photovoltaic devices and their use under various operating conditions. Here, we examine the thermal and elasto-mechanical properties of the conjugated donor polymer poly-(3-hexylthiophene) (P3HT) and the interpenetrating mixtures of P3HT and phenyl-C61-butyric acid methyl (PCBM) ester bulk heterojunction (BHJ) active layers under the application of unidirectional tensile deformation using coarse-grained molecular dynamics (CGMD) simulations. The predictions are validated against previous experimental reports as well as with earlier modeling results derived using different intermolecular force fields. Our results reveal that PCBM molecules behave as anti-plasticizers when mixed with P3HT and tend to increase the tensile modulus and glass transition temperature, while decreasing the crack-onset strain relative to pure P3HT. The variations in the mechanical properties with the composition of the BHJ active layer suggest that, in the presence of small oligomers as additives in the BHJ, the P3HT:PCBM mixture resists the anti-plasticizing effect of PCBM molecules due to the low tensile modulus of the short polymer chains.
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Affiliation(s)
- Joydeep Munshi
- Department of Mechanical Engineering & Mechanics, Lehigh University, Packard Laboratory 561, 19 Memorial Drive West, Bethlehem, PA 18015, USA.
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8
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Organic Photovoltaics: Relating Chemical Structure, Local Morphology, and Electronic Properties. TRENDS IN CHEMISTRY 2020. [DOI: 10.1016/j.trechm.2020.03.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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9
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Abstract
AbstractPhotoinduced charge generation forms the physical basis for energy conversion in organic photovoltaic (OPV) technology. The fundamental initial steps involved are absorption of light by organic semiconductors (generally π-conjugated polymers) to generate photoexcited states (Frenkel excitons) followed by charge transfer and charge separation processes in presence of suitable acceptor. The absorbed photon energy must be utilized completely for achieving maximum device efficiency. However progressive relaxation losses of instantaneously generated high-energy or hot-excited states form major bottleneck for maximum derivable voltage. This efficiency limiting factor has been challenged recently by the role of hot-carriers in efficient generation of charges. Therefore tailoring the dissociation of hot-exciton to be temporally faster than all relaxation processes could minimize the energy loss pathways. Implementation of this concept of hot-carrier photovoltaics demands critical understanding of molecular parameters that circumvent all energy relaxation processes and favor hot-carrier generation. In my dissertation work, I have examined the fate of photo-generated excitons in the context of polymer backbone and morphology, and therefore obtain a fundamental structure-function correlation in organic semiconductors.
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Affiliation(s)
- Palas Roy
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai-400005, India
- School of Chemistry, University of East Anglia, Norwich NR4 7TJ, UK
| | - Jyotishman Dasgupta
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai-400005, India
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10
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Effects of Intra- and Interchain Interactions on Exciton Dynamics of PTB7 Revealed by Model Oligomers. Molecules 2020; 25:molecules25102441. [PMID: 32456192 PMCID: PMC7287679 DOI: 10.3390/molecules25102441] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/16/2020] [Accepted: 05/22/2020] [Indexed: 11/28/2022] Open
Abstract
Recent studies have shown that molecular aggregation structures in precursor solutions of organic photovoltaic (OPV) polymers have substantial influence on polymer film morphology, exciton and charge carrier transport dynamics, and hence, the resultant device performance. To distinguish photophysical impacts due to increasing π-conjugation from chain lengthening and π–π stacking from single/multi chain aggregation in solution and film, we used oligomers of a well-studied charge transfer polymer PTB7 with different lengths as models to reveal intrinsic photophysical properties of a conjugated segment in the absence of inter-segment aggregation. In comparison with previously studied photophysical properties in polymeric PTB7, we found that oligomer dynamics are dominated by a process of planarization of the conjugated backbone into a quinoidal structure that resembles the self-folded polymer and that, when its emission is isolated, this quinoidal excited state resembling the planar polymer chain exhibits substantial charge transfer character via solvent-dependent emission shifts. Furthermore, the oligomers distinctly lack the long-lived charge separated species characteristic of PTB7, suggesting that the progression from charge transfer character in isolated chains to exciton splitting in neat polymer solution is modulated by the interchain interactions enabled by self-folding.
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11
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Hiszpanski AM, Gallagher B, Chellappan K, Li P, Liu S, Kim H, Han J, Kailkhura B, Buttler DJ, Han TYJ. Nanomaterial Synthesis Insights from Machine Learning of Scientific Articles by Extracting, Structuring, and Visualizing Knowledge. J Chem Inf Model 2020; 60:2876-2887. [PMID: 32286818 DOI: 10.1021/acs.jcim.0c00199] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nanomaterials of varying compositions and morphologies are of interest for many applications from catalysis to optics, but the synthesis of nanomaterials and their scale-up are most often time-consuming and Edisonian processes. Information gleaned from the scientific literature can help inform and accelerate nanomaterials development, but again, searching the literature and digesting the information are time-consuming manual processes for researchers. To help address these challenges, we developed scientific article-processing tools that extract and structure information from the text and figures of nanomaterials articles, thereby enabling the creation of a personalized knowledgebase for nanomaterials synthesis that can be mined to help inform further nanomaterials development. Starting with a corpus of ∼35k nanomaterials-related articles, we developed models to classify articles according to the nanomaterial composition and morphology, extract synthesis protocols from within the articles' text, and extract, normalize, and categorize chemical terms within synthesis protocols. We demonstrate the efficiency of the proposed pipeline on an expert-labeled set of nanomaterials synthesis articles, achieving 100% accuracy on composition prediction, 95% accuracy on morphology prediction, 0.99 AUC on protocol identification, and up to a 0.87 F1-score on chemical entity recognition. In addition to processing articles' text, microscopy images of nanomaterials within the articles are also automatically identified and analyzed to determine the nanomaterials' morphologies and size distributions. To enable users to easily explore the database, we developed a complementary browser-based visualization tool that provides flexibility in comparing across subsets of articles of interest. We use these tools and information to identify trends in nanomaterials synthesis, such as the correlation of certain reagents with various nanomaterial morphologies, which is useful in guiding hypotheses and reducing the potential parameter space during experimental design.
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Affiliation(s)
- Anna M Hiszpanski
- Materials Science Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Brian Gallagher
- Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Karthik Chellappan
- Global Security Computing Applications Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Peggy Li
- Global Security Computing Applications Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Shusen Liu
- Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Hyojin Kim
- Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Jinkyu Han
- Materials Science Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Bhavya Kailkhura
- Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - David J Buttler
- Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Thomas Yong-Jin Han
- Materials Science Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
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12
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Irgen-Gioro S, Roy P, Padgaonkar S, Harel E. Low energy excited state vibrations revealed in conjugated copolymer PCDTBT. J Chem Phys 2020; 152:044201. [DOI: 10.1063/1.5132299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Shawn Irgen-Gioro
- Department of Chemistry, Northwestern University, 2145 Sheridan Rd. Evanston, Illinois 60208, USA
| | - Palas Roy
- Department of Chemistry, Northwestern University, 2145 Sheridan Rd. Evanston, Illinois 60208, USA
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Suyog Padgaonkar
- Department of Chemistry, Northwestern University, 2145 Sheridan Rd. Evanston, Illinois 60208, USA
| | - Elad Harel
- Department of Chemistry, Northwestern University, 2145 Sheridan Rd. Evanston, Illinois 60208, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
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13
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Schwarz KN, Geraghty PB, Mitchell VD, Khan SUZ, Sandberg OJ, Zarrabi N, Kudisch B, Subbiah J, Smith TA, Rand BP, Armin A, Scholes GD, Jones DJ, Ghiggino KP. Reduced Recombination and Capacitor-like Charge Buildup in an Organic Heterojunction. J Am Chem Soc 2020; 142:2562-2571. [PMID: 31922408 DOI: 10.1021/jacs.9b12526] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Organic photovoltaic (OPV) efficiencies continue to rise, raising their prospects for solar energy conversion. However, researchers have long considered how to suppress the loss of free carriers by recombination-poor diffusion and significant Coulombic attraction can cause electrons and holes to encounter each other at interfaces close to where they were photogenerated. Using femtosecond transient spectroscopies, we report the nanosecond grow-in of a large transient Stark effect, caused by nanoscale electric fields of ∼487 kV/cm between photogenerated free carriers in the device active layer. We find that particular morphologies of the active layer lead to an energetic cascade for charge carriers, suppressing pathways to recombination, which is ∼2000 times less than predicted by Langevin theory. This in turn leads to the buildup of electric charge in donor and acceptor domains-away from the interface-resistant to bimolecular recombination. Interestingly, this signal is only experimentally obvious in thick films due to the different scaling of electroabsorption and photoinduced absorption signals in transient absorption spectroscopy. Rather than inhibiting device performance, we show that devices up to 600 nm thick maintain efficiencies of >8% because domains can afford much higher carrier densities. These observations suggest that with particular nanoscale morphologies the bulk heterojunction can go beyond its established role in charge photogeneration and can act as a capacitor, where adjacent free charges are held away from the interface and can be protected from bimolecular recombination.
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Affiliation(s)
| | | | | | | | - Oskar J Sandberg
- Department of Physics , Swansea University , Singleton Park , Swansea , Wales SA2 8PP , United Kingdom
| | - Nasim Zarrabi
- Department of Physics , Swansea University , Singleton Park , Swansea , Wales SA2 8PP , United Kingdom
| | | | | | | | | | - Ardalan Armin
- Department of Physics , Swansea University , Singleton Park , Swansea , Wales SA2 8PP , United Kingdom
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14
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Jones LO, Mosquera MA, Fu B, Schatz GC, Marks TJ, Ratner MA. Quantum Interference and Substantial Property Tuning in Conjugated Z- ortho-Regio-Resistive Organic (ZORRO) Junctions. NANO LETTERS 2019; 19:8956-8963. [PMID: 31682761 DOI: 10.1021/acs.nanolett.9b03849] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Coherence is a significant factor in nanoscale electronic insulator technology and necessitates an understanding of the structure-property relationship between constructive and destructive quantum interference. This is particularly important in organic dielectric circuitry, which is the subject of this work. It is known that molecular wires composed of (i) meta-substituted phenylene rings, (ii) cross-conjugated double bonds (orthogonal to the molecular long axis), and (iii) single bonds can dramatically reduce electrical transmission. Here we add to these tools the use of an unexplored molecular shape to create strong and counterintuitive interference: a fully conjugated molecular wire with a structure that is forced back on itself in a Z shape, thereby exhibiting remarkably low conductance (G = 0.43 × 10-9 S) even though the phenylene arrangements are ortho- rather than meta-disposed. We call these Z-shaped molecules having ultralow conduction Z-ortho-regio-resistive organics (ZORROs). Here we analyze a series of ZORRO molecules and find them to have significant insulating properties in the coherent electron-transport regime due to interfering transmission pathways in the phenylene rings. Importantly, we find that both electron-withdrawing (fluorine) and electron-donating (methoxy) substituents enhance the transmission, which is not desirable. The former is due to the suppression of the destructive quantum interference at the F site, thereby enhancing the overall transmission, much like a Büttiker probe. The latter is due to a methoxy unit resonance additive effect, akin to oxygen doping, and positively contributes to the transmission. We then examine the effects of replacing the phenylene rings with 4,5- and 3,4-disubstituted thiophenes and how this ZORRO modification further reduces the transmission. An ultralow conductance of 0.13 × 10-9 S and a relatively high dielectric constant (εr) of ∼5 are predicted for the 3,4-thiophene ZORRO derivative, which closely resembles two cross-conjugated units, making it an intriguing candidate for a gate dielectric material.
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Affiliation(s)
- Leighton O Jones
- Department of Chemistry and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
| | - Martín A Mosquera
- Department of Chemistry and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
| | - Bo Fu
- Department of Chemistry and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
| | - George C Schatz
- Department of Chemistry and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
| | - Tobin J Marks
- Department of Chemistry and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
| | - Mark A Ratner
- Department of Chemistry and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
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16
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Marmolejo-Valencia AF, Mata-Pinzón Z, Dominguez L, Amador-Bedolla C. Atomistic simulations of bulk heterojunctions to evaluate the structural and packing properties of new predicted donors in OPVs. Phys Chem Chem Phys 2019; 21:20315-20326. [PMID: 31495832 DOI: 10.1039/c9cp04041b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Organic photovoltaic materials (OPVs), with low cost and structure flexibility, are of great interest and importance for their application in solar cell device development. However, the optimization of new OPV structures and the study of the structure arrangements and packing morphologies when materials are blended takes time and consumes raw materials, thus theoretical models could be of considerable value. In this work, we performed molecular dynamics simulations of present OPVs to understand the morphological packing of the donor-acceptor (DA) phases and DA heterojunction during evaporation and annealing processes, following inter and intramolecular properties like frontier orbitals, π-π stacking, coordination, distances, angles, and aggregation. Our considered donor molecules were selected from already proved experimental studies and also from predicted optimal compounds, designed through high throughput studies. The acceptor molecule employed in all our studied systems was PCBM ([6,6]-phenyl-C61-butyric acid methyl ester). Furthermore, we also analyze the influence of including different lateral aliphatic chains on the structural properties of the resulting DA packing morphologies. Our results can guide the design of new OPVs and subsequent studies applying charge transport and charge separation models.
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Affiliation(s)
- Andrés F Marmolejo-Valencia
- Facultad de Química, Universidad Nacional Autónoma de México, Av. Universidad 3000, Coyoacán, CDMX 04510, Mexico.
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17
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Matt C, Lombeck F, Sommer M, Biskup T. Impact of Side Chains of Conjugated Polymers on Electronic Structure: A Case Study. Polymers (Basel) 2019; 11:E870. [PMID: 31086059 PMCID: PMC6572471 DOI: 10.3390/polym11050870] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/26/2019] [Accepted: 05/08/2019] [Indexed: 11/22/2022] Open
Abstract
Processing from solution is a crucial aspect of organic semiconductors, as it is at the heart of the promise of easy and inexpensive manufacturing of devices. Introducing alkyl side chains is an approach often used to increase solubility and enhance miscibility in blends. The influence of these side chains on the electronic structure, although highly important for a detailed understanding of the structure-function relationship of these materials, is still barely understood. Here, we use time-resolved electron paramagnetic resonance spectroscopy with its molecular resolution to investigate the role of alkyl side chains on the polymer PCDTBT and a series of its building blocks with increasing length. Comparing our results to the non-hexylated compounds allows us to distinguish four different factors determining exciton delocalization. Detailed quantum-chemical calculations (DFT) allows us to further interpret our spectroscopic data and to relate our findings to the molecular geometry. Alkylation generally leads to more localized excitons, most prominent only for the polymer. Furthermore, singlet excitons are more delocalized than the corresponding triplet excitons, despite the larger dihedral angles within the backbone found for the singlet-state geometries. Our results show TREPR spectroscopy of triplet excitons to be well suited for investigating crucial aspects of the structure-function relationship of conjugated polymers used as organic semiconductors on a molecular basis.
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Affiliation(s)
- Clemens Matt
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104 Freiburg, Germany.
| | - Florian Lombeck
- Institut für Makromolekulare Chemie, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Straße 31, 79104 Freiburg, Germany.
| | - Michael Sommer
- Institut für Makromolekulare Chemie, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Straße 31, 79104 Freiburg, Germany.
| | - Till Biskup
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104 Freiburg, Germany.
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Munshi J, Dulal R, Chien T, Chen W, Balasubramanian G. Solution Processing Dependent Bulk Heterojunction Nanomorphology of P3HT/PCBM Thin Films. ACS APPLIED MATERIALS & INTERFACES 2019; 11:17056-17067. [PMID: 30966744 DOI: 10.1021/acsami.9b02719] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Mixtures of poly(3-hexyl-thiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) have been widely employed as donor and acceptor materials, respectively, for the active layer of the bulk heterojunction (BHJ) organic solar cells. Experiments are able to provide only limited insights on the dynamics of blend morphology of these organic materials because of the challenges in extracting microstructural characterization amidst the poor contrast in electron microscopy. We present results from coarse-grained molecular dynamics simulations (CGMD) describing the morphological evolution of P3HT/PCBM active layer under solution processing in chlorobenzene (CB). We examine the impact of various processing parameters such as weight ratio, degree of polymerization (DOP), thermal annealing, and preheating on the BHJ active layers using morphological characterizations from atomic trajectories. Simulated diffraction patterns are compared with experimental results of X-ray diffraction and Small Angle X-ray Scattering (SAXS). Both simulated scattering and experimental X-ray diffraction and X-ray scattering measurements reveal increase in crystallinity for P3HT upon annealing until PCBM weight fraction ∼50%. The solubility of PCBM being greater in CB than that of P3HT facilitates the phase separation of the polymer during early stages of solvent evaporation. An increase in the average size of the P3HT domain relative to the preannealed morphology, is due to phase segregation and crystallization of the polymer upon annealing. Percolation for PCBM remains unchanged until PCBM constitutes at least one-half of the composition. Although 1.0:2.0 weight ratio is predicted to be ideal for balanced charge transport, 1.0:1.0 weight ratio is the most beneficial of overall power conversion based on exciton generation and charge separation at the interface. DOP of P3HT molecules is another important design variable as larger P3HT molecules tend to entangle more often deteriorating molecular order of P3HT phase in the active layer. Preheating the ternary mixture of P3HT, PCBM, and CB modifies the structural order and morphology of the BHJ due to changes in PCBM diffusion into the P3HT phase.
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Affiliation(s)
- Joydeep Munshi
- Department of Mechanical Engineering and Mechanics , Lehigh University , Bethlehem , Pennsylvania 18015 , United States
| | - Rabindra Dulal
- Department of Physics and Astronomy , University of Wyoming , Laramie , Wyoming 82071 , United States
| | - TeYu Chien
- Department of Physics and Astronomy , University of Wyoming , Laramie , Wyoming 82071 , United States
| | - Wei Chen
- Department of Mechanical Engineering , Northwestern University , Evanston , Illinois 60208 , United States
| | - Ganesh Balasubramanian
- Department of Mechanical Engineering and Mechanics , Lehigh University , Bethlehem , Pennsylvania 18015 , United States
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19
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Koçak O, Duru IP, Yavuz I. Charge Transfer and Interface Effects in Co‐Assembled Circular Donor/Acceptor Complexes for Organic Photovoltaics. ADVANCED THEORY AND SIMULATIONS 2019. [DOI: 10.1002/adts.201800194] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Olkan Koçak
- Department of PhysicsMarmara University 34722 Ziverbey Istanbul Turkey
| | - Izzet Paruğ Duru
- Department of PhysicsMarmara University 34722 Ziverbey Istanbul Turkey
| | - Ilhan Yavuz
- Department of PhysicsMarmara University 34722 Ziverbey Istanbul Turkey
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20
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Biskup T. Structure-Function Relationship of Organic Semiconductors: Detailed Insights From Time-Resolved EPR Spectroscopy. Front Chem 2019; 7:10. [PMID: 30775359 PMCID: PMC6367236 DOI: 10.3389/fchem.2019.00010] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 01/07/2019] [Indexed: 11/22/2022] Open
Abstract
Organic photovoltaics (OPV) is a promising technology to account for the increasing demand for energy in form of electricity. Whereas the last decades have seen tremendous progress in the field witnessed by the steady increase in efficiency of OPV devices, we still lack proper understanding of fundamental aspects of light-energy conversion, demanding for systematic investigation on a fundamental level. A detailed understanding of the electronic structure of semiconducting polymers and their building blocks is essential to develop efficient materials for organic electronics. Illuminating conjugated polymers not only leads to excited states, but sheds light on some of the most important aspects of device efficiency in organic electronics as well. The interplay between electronic structure, morphology, flexibility, and local ordering, while at the heart of structure-function relationship of organic electronic materials, is still barely understood. (Time-resolved) electron paramagnetic resonance (EPR) spectroscopy is particularly suited to address these questions, allowing one to directly detect paramagnetic states and to reveal their spin-multiplicity, besides its clearly superior spectral resolution compared to optical methods. This article aims at giving a non-specialist audience an overview of what EPR spectroscopy and particularly its time-resolved variant (TREPR) can contribute to unraveling aspects of structure-function relationship in organic semiconductors.
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Affiliation(s)
- Till Biskup
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
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21
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Lankevich V, Bittner ER. Relating free energy and open-circuit voltage to disorder in organic photovoltaic systems. J Chem Phys 2018; 149:244123. [DOI: 10.1063/1.5050506] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- V. Lankevich
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, USA
| | - E. R. Bittner
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, USA
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22
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Gedefaw D, Hedström S, Xia Y, Persson P, Andersson MR. Design, Synthesis and Computational Study of Fluorinated Quinoxaline-Oligothiophene-based Conjugated Polymers with Broad Spectral Coverage. Chemphyschem 2018; 19:3393-3400. [PMID: 30381883 DOI: 10.1002/cphc.201800814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 10/30/2018] [Indexed: 11/07/2022]
Abstract
Donor-acceptor (D-A) copolymers typically show two absorption peaks in the visible region, flanking a valley region of limited absorptivity. One strategy for more panchromatic light harvesting is to incorporate side-groups orthogonal to the polymer backbone, which enable 2D π conjugation and can give rise to additional absorption peaks. Here we design and synthesize two D-A polymers which both carry a fluorinated quinoxaline acceptor unit, but while P1 includes a benzodithiophene donor moiety with thiophene side-groups (2D-BDT), the P2 polymer lacks 2D conjugation in its simpler pentathiophene donor segment. The P1 polymer consequently shows an atypical absorption profile with more panchromatic absorption with no apparent valley in the spectrum. In order to understand the structure-electronic relations, the optical and electrochemical properties were predicted using a previously developed computational approach. The predicted optical properties show very good agreement with the experimental results. Solar cells made from P1 show a short-circuit current more than twice as large as P2, attributed to its enhanced spectral coverage. However, poor fill factors limit the preliminary power conversion efficiencies to 3.3 % for P1 and 1.0 % for P2 as blended with PCBM[70] in a 1 : 1.5 (w/w) ratio.
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Affiliation(s)
- Desta Gedefaw
- School of Biological and Chemical Sciences, The University of South Pacific, LaucalaCampus, Suva, Fiji.,Flinders Institute for Nanoscale Science and Technology, Flinders University, Sturt Road, Bedford Park, Adelaide, SA 5042, Australia
| | - Svante Hedström
- Department of Physics, Albanova University Center, Stockholm University, 10691, Stockholm, Sweden.,Division of Theoretical Chemistry, Lund University, P. O. Box 124, S-221 00, Lund, Sweden
| | - Yuxin Xia
- Department of Physics, Chemistry and Biology, Linköping University, SE-581 83, Linköping, Sweden
| | - Petter Persson
- Division of Theoretical Chemistry, Lund University, P. O. Box 124, S-221 00, Lund, Sweden
| | - Mats R Andersson
- Flinders Institute for Nanoscale Science and Technology, Flinders University, Sturt Road, Bedford Park, Adelaide, SA 5042, Australia
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23
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Nunzi JM, Lebel O. Revisiting the Optimal Nano-Morphology: Towards Amorphous Organic Photovoltaics. CHEM REC 2018; 19:1028-1038. [PMID: 30548964 DOI: 10.1002/tcr.201800158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/14/2018] [Indexed: 11/12/2022]
Abstract
Organic photovoltaic cells commonly use an active layer with a polycrystalline bulk heterojunction. However, for simplifying the fabrication process, it may be worthwhile to use an amorphous active layer to lessen the burden on processing to achieve optimal performance. While polymers can adopt amorphous phases, molecular glasses, small molecules that can readily form glassy phases and do not crystallize over time, offer an appealing alternative, being monodisperse species. Our group has developed a series of reactive molecular glasses that can be covalently bonded to chromophores to form glass-forming adducts, and this strategy has been used to synthesize glass-forming donor and acceptor materials. Herein, the results of devices incorporating these materials in either partially or fully amorphous active layers are summarized. Additionally, these molecular glasses can be used as ternary components in crystalline systems to enhance efficiency without perturbing the morphology.
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Affiliation(s)
- Jean-Michel Nunzi
- Department of Chemistry, Department of Physics, Engineering Physics and Astronomy, Queen's University, Kingston, ON, Canada, K7L 3N6
| | - Olivier Lebel
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, ON, Canada, K7K 7B4
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24
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Reid DR, Jackson NE, Bourque AJ, Snyder CR, Jones RL, de Pablo JJ. Aggregation and Solubility of a Model Conjugated Donor-Acceptor Polymer. J Phys Chem Lett 2018; 9:4802-4807. [PMID: 30063357 PMCID: PMC6260830 DOI: 10.1021/acs.jpclett.8b01738] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
In conjugated polymers, solution-phase structure and aggregation exert a strong influence on device morphology and performance, making understanding solubility crucial for rational design. Using atomistic molecular dynamics (MD) and free-energy sampling algorithms, we examine the aggregation and solubility of the polymer PTB7, studying how side-chain structure can be modified to control aggregation. We demonstrate that free-energy sampling can be used to effectively screen polymer solubility in a variety of solvents but that solubility parameters derived from MD are not predictive. We then study the aggregation of variants of PTB7 including those with linear (octyl), branched (2-ethylhexyl), and cleaved (methyl) side chains, in a selection of explicit solvents and additives. Energetic analysis demonstrates that while side chains do disrupt polymer backbone stacking, solvent exclusion is a critical factor controlling polymer solubility.
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Affiliation(s)
- Daniel R Reid
- Institute for Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
| | - Nicholas E Jackson
- Institute for Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
- Institute for Molecular Engineering , Argonne National Laboratory , Lemont , Illinois 60439 , United States
| | - Alexander J Bourque
- National Institute of Standards and Technology (NIST) , Gaithersburg , Maryland 20899 , United States
| | - Chad R Snyder
- National Institute of Standards and Technology (NIST) , Gaithersburg , Maryland 20899 , United States
| | - Ronald L Jones
- National Institute of Standards and Technology (NIST) , Gaithersburg , Maryland 20899 , United States
| | - Juan J de Pablo
- Institute for Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
- Institute for Molecular Engineering , Argonne National Laboratory , Lemont , Illinois 60439 , United States
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25
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Ang ST, Pal A, Manzhos S. Comparison of optical absorption spectra of organic molecules and aggregates computed from real frequency dependent polarizability to TD-DFT and the dipole approximation. J Chem Phys 2018; 149:044114. [DOI: 10.1063/1.5040723] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Siong Tuan Ang
- Department of Mechanical Engineering, National University of Singapore, Block EA #07-08, 9 Engineering Drive 1, Singapore 117576
| | - Amrita Pal
- Department of Mechanical Engineering, National University of Singapore, Block EA #07-08, 9 Engineering Drive 1, Singapore 117576
| | - Sergei Manzhos
- Department of Mechanical Engineering, National University of Singapore, Block EA #07-08, 9 Engineering Drive 1, Singapore 117576
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26
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McDowell C, Abdelsamie M, Toney MF, Bazan GC. Solvent Additives: Key Morphology-Directing Agents for Solution-Processed Organic Solar Cells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1707114. [PMID: 29900605 DOI: 10.1002/adma.201707114] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 02/17/2018] [Indexed: 05/12/2023]
Abstract
Organic photovoltaics (OPV) have the advantage of possible fabrication by energy-efficient and cost-effective deposition methods, such as solution processing. Solvent additives can provide fine control of the active layer morphology of OPVs by influencing film formation during solution processing. As such, solvent additives form a versatile method of experimental control for improving organic solar cell device performance. This review provides a brief history of solution-processed bulk heterojunction OPVs and the advent of solvent additives, putting them into context with other methods available for morphology control. It presents the current understanding of how solvent additives impact various mechanisms of phase separation, enabled by recent advances in in situ morphology characterization. Indeed, understanding solvent additives' effects on film formation has allowed them to be applied and combined effectively and synergistically to boost OPV performance. Their success as a morphology control strategy has also prompted the use of solvent additives in related organic semiconductor technologies. Finally, the role of solvent additives in the development of next-generation OPV active layers is discussed. Despite concerns over their environmental toxicity and role in device instability, solvent additives remain relevant morphological directing agents as research interests evolve toward nonfullerene acceptors, ternary blends, and environmentally sustainable solvents.
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Affiliation(s)
- Caitlin McDowell
- Center for Polymers and Organic Solids, Departments of Chemistry and Biochemistry and Materials, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Maged Abdelsamie
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Building 137, Menlo Park, CA, 94025, USA
| | - Michael F Toney
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Building 137, Menlo Park, CA, 94025, USA
| | - Guillermo C Bazan
- Center for Polymers and Organic Solids, Departments of Chemistry and Biochemistry and Materials, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
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27
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Matt C, Meyer DL, Lombeck F, Sommer M, Biskup T. TBT Entirely Dominates the Electronic Structure of the Conjugated Copolymer PCDTBT: Insights from Time-Resolved Electron Paramagnetic Resonance Spectroscopy. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00791] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Clemens Matt
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104 Freiburg, Germany
| | - Deborah L. Meyer
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104 Freiburg, Germany
| | - Florian Lombeck
- Institut für Makromolekulare Chemie, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Straße 31, 79104 Freiburg, Germany
| | - Michael Sommer
- Institut für Makromolekulare Chemie, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Straße 31, 79104 Freiburg, Germany
| | - Till Biskup
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104 Freiburg, Germany
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28
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Nagasawa S, Al-Naamani E, Saeki A. Computer-Aided Screening of Conjugated Polymers for Organic Solar Cell: Classification by Random Forest. J Phys Chem Lett 2018; 9:2639-2646. [PMID: 29733216 DOI: 10.1021/acs.jpclett.8b00635] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Owing to the diverse chemical structures, organic photovoltaic (OPV) applications with a bulk heterojunction framework have greatly evolved over the last two decades, which has produced numerous organic semiconductors exhibiting improved power conversion efficiencies (PCEs). Despite the recent fast progress in materials informatics and data science, data-driven molecular design of OPV materials remains challenging. We report a screening of conjugated molecules for polymer-fullerene OPV applications by supervised learning methods (artificial neural network (ANN) and random forest (RF)). Approximately 1000 experimental parameters including PCE, molecular weight, and electronic properties are manually collected from the literature and subjected to machine learning with digitized chemical structures. Contrary to the low correlation coefficient in ANN, RF yields an acceptable accuracy, which is twice that of random classification. We demonstrate the application of RF screening for the design, synthesis, and characterization of a conjugated polymer, which facilitates a rapid development of optoelectronic materials.
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Affiliation(s)
- Shinji Nagasawa
- Department of Applied Chemistry, Graduate School of Engineering , Osaka University , 2-1 Yamadaoka , Suita, Osaka 565-0871 , Japan
| | - Eman Al-Naamani
- Department of Applied Chemistry, Graduate School of Engineering , Osaka University , 2-1 Yamadaoka , Suita, Osaka 565-0871 , Japan
| | - Akinori Saeki
- Department of Applied Chemistry, Graduate School of Engineering , Osaka University , 2-1 Yamadaoka , Suita, Osaka 565-0871 , Japan
- Precursory Research for Embryonic Science and Technology (PRESTO) , Japan Science and Technology Agency , 4-1-8 Honcho , Kawaguchi, Saitama 332-0012 , Japan
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29
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Chen JH, Liu CK, Chang WC, Sah PT, Chan LH. Structure-Function Relationships in PMA and PMAT Series Copolymers for Polymer Solar Cells. Polymers (Basel) 2018; 10:E384. [PMID: 30966419 PMCID: PMC6415455 DOI: 10.3390/polym10040384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 03/21/2018] [Accepted: 03/27/2018] [Indexed: 11/27/2022] Open
Abstract
Two series (PMA and PMAT) of two-dimensional donor-acceptor copolymers consisting of a 3,4-bis(4-bromophenyl)maleimide derivative and triphenylamine with a conjugated side chain were designed and synthesized to probe their structure-function relationships for use in bulk heterojunction (BHJ) polymer solar cells (PSCs). The difference between PMA- and PMAT-series is the conjugated side chain length on the triphenylamine unit. By extending the side chain length, and by attaching various acceptor end groups to the side chain, the electronic and photophysical properties of these copolymers, as well as subsequent device performance, were significantly affected. Two series of copolymers showed broad absorption in the visible region with two obvious peaks. With increasing electron-withdrawing strength of the acceptor end groups, the intramolecular charge transfer peak becomes progressively red-shifted. Highest occupied molecular orbital (HOMO) levels in each copolymer series are similar, but lowest unoccupied molecular orbital (LUMO) levels are dictated by the acceptors. BHJ PSCs composed of the copolymers as a donor and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as an acceptor in 1:2 weight ratio were fabricated and characterized. PSCs based on PMA- and PMAT-series copolymers had power conversion efficiencies (PCEs) ranging from 2.05⁻2.16% and 3.14⁻4.01%, respectively. These results indicate that subtle tuning of the chemical structure can significantly influence PSC device performance.
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Affiliation(s)
- Jhe-Han Chen
- Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Nantou 54561, Taiwan.
| | - Chi-Kan Liu
- Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Nantou 54561, Taiwan.
| | - Wei-Che Chang
- Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Nantou 54561, Taiwan.
| | - Pai-Tao Sah
- Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Nantou 54561, Taiwan.
| | - Li-Hsin Chan
- Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Nantou 54561, Taiwan.
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30
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Acocella A, Höfinger S, Haunschmid E, Pop SC, Narumi T, Yasuoka K, Yasui M, Zerbetto F. Structural determinants in the bulk heterojunction. Phys Chem Chem Phys 2018; 20:5708-5720. [PMID: 29410990 DOI: 10.1039/c7cp08435h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Photovoltaics is one of the key areas in renewable energy research with remarkable progress made every year. Here we consider the case of a photoactive material and study its structural composition and the resulting consequences for the fundamental processes driving solar energy conversion. A multiscale approach is used to characterize essential molecular properties of the light-absorbing layer. A selection of bulk-representative pairs of donor/acceptor molecules is extracted from the molecular dynamics simulation of the bulk heterojunction and analyzed at increasing levels of detail. Significantly increased ground state energies together with an array of additional structural characteristics are identified that all point towards an auxiliary role of the material's structural organization in mediating charge-transfer and -separation. Mechanistic studies of the type presented here can provide important insights into fundamental principles governing solar energy conversion in next-generation photovoltaic devices.
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Affiliation(s)
- Angela Acocella
- Department of Chemistry "G. Ciamician", University of Bologna, via F. Selmi 2, 40126 Bologna, Italy.
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31
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Meyer DL, Matsidik R, Huettner S, Sommer M, Biskup T. Solvent-mediated aggregate formation of PNDIT2: decreasing the available conformational subspace by introducing locally highly ordered domains. Phys Chem Chem Phys 2018; 20:2716-2723. [DOI: 10.1039/c7cp07725d] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Time-resolved EPR spectroscopy proves aggregation of PNDIT2 to introduce highly ordered domains and to change the exciton delocalisation mode.
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Affiliation(s)
- Deborah L. Meyer
- Albert-Ludwigs-Universität Freiburg
- Institut für Physikalische Chemie
- Albertstraße 21
- 79104 Freiburg
- Germany
| | - Rukiya Matsidik
- Albert-Ludwigs-Universität Freiburg
- Institut für Makromolekulare Chemie
- Stefan-Meier-Straße 31
- 79104 Freiburg
- Germany
| | - Sven Huettner
- Universität Bayreuth
- Makromolekulare Chemie
- Universitätsstraße 30
- 95440 Bayreuth
- Germany
| | - Michael Sommer
- Albert-Ludwigs-Universität Freiburg
- Institut für Makromolekulare Chemie
- Stefan-Meier-Straße 31
- 79104 Freiburg
- Germany
| | - Till Biskup
- Albert-Ludwigs-Universität Freiburg
- Institut für Physikalische Chemie
- Albertstraße 21
- 79104 Freiburg
- Germany
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32
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Manley EF, Strzalka J, Fauvell TJ, Jackson NE, Leonardi MJ, Eastham ND, Marks TJ, Chen LX. In Situ GIWAXS Analysis of Solvent and Additive Effects on PTB7 Thin Film Microstructure Evolution during Spin Coating. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1703933. [PMID: 28990271 DOI: 10.1002/adma.201703933] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/25/2017] [Indexed: 06/07/2023]
Abstract
The influence of solvent and processing additives on the pathways and rates of crystalline morphology formation for spin-coated semiconducting PTB7 (poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)-carbonyl]-thieno[3,4-b]thiophenediyl]]) thin films is investigated by in situ grazing incidence wide-angle X-ray scattering (GIWAXS) and optical reflectance, to better understand polymer solar cell (PSC) optimization approaches. In situ characterization of PTB7 film formation from chloroform (CF), chlorobenzene (CB), and 1,2-dichlorobenzene (DCB) solutions, as well as CB solutions with 1% and 3% v/v of the processing additives 1-chloronapthalene (CN), diphenylether (DPE), and 1,8-diiodooctane (DIO), reveals multiple crystallization pathways with: (i) single-solvent systems exhibiting rapid (<3 s) crystallization after a solvent boiling point-dependent film thinning transition, (ii) solvent + additive systems exhibiting different crystallization pathways and crystallite formation times from minutes (CN, DPE) to 1.5 h (DIO). Identifying crystalline intermediates has implications for bulk-heterojunction PSC morphology optimization via optimized spin-casting processes.
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Affiliation(s)
- Eric F Manley
- Department of Chemistry and the Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL, 60439, USA
| | - Joseph Strzalka
- X-ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Thomas J Fauvell
- Department of Chemistry and the Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL, 60439, USA
| | - Nicholas E Jackson
- Department of Chemistry and the Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Matthew J Leonardi
- Department of Chemistry and the Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Nicholas D Eastham
- Department of Chemistry and the Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Tobin J Marks
- Department of Chemistry and the Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Lin X Chen
- Department of Chemistry and the Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL, 60439, USA
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33
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Dwyer RP, Nathan SR, Marohn JA. Microsecond photocapacitance transients observed using a charged microcantilever as a gated mechanical integrator. SCIENCE ADVANCES 2017; 3:e1602951. [PMID: 28691085 PMCID: PMC5479705 DOI: 10.1126/sciadv.1602951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 04/17/2017] [Indexed: 05/29/2023]
Abstract
How light is converted to electricity in blends of organic donor and acceptor molecules is an unsettled question, partly because the spatial heterogeneity present in these blends makes them challenging to characterize. Although scanned-probe measurements have provided crucially important microscopic insights into charge generation and transport in these blends, achieving the subnanosecond time resolution needed to directly observe the fate of photogenerated charges has proven difficult. We use a charged microcantilever as a gated mechanical integrator to record photocapacitance indirectly by measuring the accumulated change in cantilever phase as a function of the time delay between precisely synchronized voltage and light pulses. In contrast with previous time-resolved scanned-probe photocapacitance measurements, the time resolution of this method is set by the rise and fall time of the voltage and light pulses and not by the inverse detection bandwidth. We demonstrate in an organic donor-acceptor blend the ability of this indirect, "phase-kick" technique to record multiexponential photocapacitance transients on time scales ranging from 40 μs to 10 ms. The technique's ability to measure subcycle, nanosecond charge dynamics is demonstrated by measuring the tens of nanosecond sample electrical charging time.
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34
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Langis-Barsetti S, Maris T, Wuest JD. Molecular Organization of 2,1,3-Benzothiadiazoles in the Solid State. J Org Chem 2017; 82:5034-5045. [DOI: 10.1021/acs.joc.6b02778] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Thierry Maris
- Département de Chimie, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - James D. Wuest
- Département de Chimie, Université de Montréal, Montréal, Québec H3C 3J7, Canada
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35
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Meyer DL, Lombeck F, Huettner S, Sommer M, Biskup T. Direct S 0→T Excitation of a Conjugated Polymer Repeat Unit: Unusual Spin-Forbidden Transitions Probed by Time-Resolved Electron Paramagnetic Resonance Spectroscopy. J Phys Chem Lett 2017; 8:1677-1682. [PMID: 28345918 DOI: 10.1021/acs.jpclett.7b00644] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A detailed understanding of the electronic structure of semiconducting polymers and their building blocks is essential to develop efficient materials for organic electronics. (Time-resolved) electron paramagnetic resonance (EPR) is particularly suited to address these questions, allowing one to directly detect paramagnetic states and to reveal their spin-multiplicity, besides its clearly superior resolution compared to optical methods. We present here evidence for a direct S0→T optical excitation of distinct triplet states in the repeat unit of a conjugated polymer used in organic photovoltaics. These states differ in their electronic structure from those populated via intersystem crossing from excited singlet states. This is an additional and so far unconsidered route to triplet states with potentially high impact on efficiency of organic electronic devices.
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Affiliation(s)
| | - Florian Lombeck
- Optoelectronics Group, University of Cambridge , Cavendish Laboratory, Cambridge CB3 0HE, United Kingdom
| | - Sven Huettner
- Organic and Hybrid Electronics, Macromolecular Chemistry I, Universität Bayreuth , 95440 Bayreuth, Germany
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36
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Alessandri R, Uusitalo JJ, de Vries AH, Havenith RWA, Marrink SJ. Bulk Heterojunction Morphologies with Atomistic Resolution from Coarse-Grain Solvent Evaporation Simulations. J Am Chem Soc 2017; 139:3697-3705. [PMID: 28209056 PMCID: PMC5355903 DOI: 10.1021/jacs.6b11717] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
![]()
Control
over the morphology of the active layer of bulk heterojunction
(BHJ) organic solar cells is paramount to achieve high-efficiency
devices. However, no method currently available can predict morphologies
for a novel donor–acceptor blend. An approach which allows
reaching relevant length scales, retaining chemical specificity, and
mimicking experimental fabrication conditions, and which is suited
for high-throughput schemes has been proven challenging to find. Here,
we propose a method to generate atom-resolved morphologies of BHJs
which conforms to these requirements. Coarse-grain (CG) molecular
dynamics simulations are employed to simulate the large-scale morphological
organization during solution-processing. The use of CG models which
retain chemical specificity translates into a direct path to the rational
design of donor and acceptor compounds which differ only slightly
in chemical nature. Finally, the direct retrieval of fully atomistic
detail is possible through backmapping, opening the way for improved
quantum mechanical calculations addressing the charge separation mechanism.
The method is illustrated for the poly(3-hexyl-thiophene) (P3HT)–phenyl-C61-butyric
acid methyl ester (PCBM) mixture, and found to predict morphologies
in agreement with experimental data. The effect of drying rate, P3HT
molecular weight, and thermal annealing are investigated extensively,
resulting in trends mimicking experimental findings. The proposed
methodology can help reduce the parameter space which has to be explored
before obtaining optimal morphologies not only for BHJ solar cells
but also for any other solution-processed soft matter device.
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Affiliation(s)
| | | | | | - Remco W A Havenith
- Ghent Quantum Chemistry Group, Department of Inorganic and Physical Chemistry, Ghent University , Krijgslaan 281 (S3), B-9000 Gent, Belgium
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37
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Groves C. Simulating charge transport in organic semiconductors and devices: a review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:026502. [PMID: 27991440 DOI: 10.1088/1361-6633/80/2/026502] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Charge transport simulation can be a valuable tool to better understand, optimise and design organic transistors (OTFTs), photovoltaics (OPVs), and light-emitting diodes (OLEDs). This review presents an overview of common charge transport and device models; namely drift-diffusion, master equation, mesoscale kinetic Monte Carlo and quantum chemical Monte Carlo, and a discussion of the relative merits of each. This is followed by a review of the application of these models as applied to charge transport in organic semiconductors and devices, highlighting in particular the insights made possible by modelling. The review concludes with an outlook for charge transport modelling in organic electronics.
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Affiliation(s)
- C Groves
- Durham University, School of Engineering and Computing Sciences, South Road, Durham, DH1 3LE, UK
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38
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Brédas JL, Sargent EH, Scholes GD. Photovoltaic concepts inspired by coherence effects in photosynthetic systems. NATURE MATERIALS 2016; 16:35-44. [PMID: 27994245 DOI: 10.1038/nmat4767] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 09/05/2016] [Indexed: 05/20/2023]
Abstract
The past decade has seen rapid advances in our understanding of how coherent and vibronic phenomena in biological photosynthetic systems aid in the efficient transport of energy from light-harvesting antennas to photosynthetic reaction centres. Such coherence effects suggest strategies to increase transport lengths even in the presence of structural disorder. Here we explore how these principles could be exploited in making improved solar cells. We investigate in depth the case of organic materials, systems in which energy and charge transport stand to be improved by overcoming challenges that arise from the effects of static and dynamic disorder - structural and energetic - and from inherently strong electron-vibration couplings. We discuss how solar-cell device architectures can evolve to use coherence-exploiting materials, and we speculate as to the prospects for a coherent energy conversion system. We conclude with a survey of the impacts of coherence and bioinspiration on diverse solar-energy harvesting solutions, including artificial photosynthetic systems.
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Affiliation(s)
- Jean-Luc Brédas
- Division of Physical Science and Engineering, Solar and Photovoltaics Engineering Research Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Edward H Sargent
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 3G4, Canada
| | - Gregory D Scholes
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
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39
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de Echegaray P, Mancheño MJ, Arrechea-Marcos I, Juárez R, López-Espejo G, López Navarrete JT, Ramos MM, Seoane C, Ortiz RP, Segura JL. Synthesis of Perylene Imide Diones as Platforms for the Development of Pyrazine Based Organic Semiconductors. J Org Chem 2016; 81:11256-11267. [PMID: 27791365 DOI: 10.1021/acs.joc.6b02214] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There is a great interest in peryleneimide (PI)-containing compounds given their unique combination of good electron accepting ability, high abosorption in the visible region, and outstanding chemical, thermal, and photochemical stabilities. Thus, herein we report the synthesis of perylene imide derivatives endowed with a 1,2-diketone functionality (PIDs) as efficient intermediates to easily access peryleneimide (PI)-containing organic semiconductors with enhanced absorption cross-section for the design of tunable semiconductor organic materials. Three processable organic molecular semiconductors containing thiophene and terthiophene moieties, PITa, PITb, and PITT, have been prepared from the novel PIDs. The tendency of these semiconductors for molecular aggregation have been investigated by NMR spectroscopy and supported by quantum chemical calculations. 2D NMR experiments and theoretical calculations point to an antiparallel π-stacking interaction as the most stable conformation in the aggregates. Investigation of the optical and electrochemical properties of the materials is also reported and analyzed in combination with DFT calculations. Although the derivatives presented here show modest electron mobilities of ∼10-4 cm2V-1s-1, these preliminary studies of their performance in organic field effect transistors (OFETs) indicate the potential of these new building blocks as n-type semiconductors.
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Affiliation(s)
- Paula de Echegaray
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid , 28040 Madrid, Spain
| | - María J Mancheño
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid , 28040 Madrid, Spain
| | - Iratxe Arrechea-Marcos
- Departamento de Química Física, Facultad de Ciencias, Universidad de Málaga , 29071 Málaga, Spain
| | - Rafael Juárez
- Departamento de Tecnología Química y Ambiental, Universidad Rey Juan Carlos , Madrid 28933, Spain
| | - Guzmán López-Espejo
- Departamento de Química Física, Facultad de Ciencias, Universidad de Málaga , 29071 Málaga, Spain
| | | | - María Mar Ramos
- Departamento de Tecnología Química y Ambiental, Universidad Rey Juan Carlos , Madrid 28933, Spain
| | - Carlos Seoane
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid , 28040 Madrid, Spain
| | - Rocío Ponce Ortiz
- Departamento de Química Física, Facultad de Ciencias, Universidad de Málaga , 29071 Málaga, Spain
| | - José L Segura
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid , 28040 Madrid, Spain
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40
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Liu T, Meng D, Cai Y, Sun X, Li Y, Huo L, Liu F, Wang Z, Russell TP, Sun Y. High-Performance Non-Fullerene Organic Solar Cells Based on a Selenium-Containing Polymer Donor and a Twisted Perylene Bisimide Acceptor. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2016; 3:1600117. [PMID: 27711261 PMCID: PMC5039968 DOI: 10.1002/advs.201600117] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 03/31/2016] [Indexed: 05/10/2023]
Abstract
A novel polymer donor (PBDTS-Se) is designed to match with a non-fullerene acceptor (SdiPBI-S). The corresponding solar cells show a high efficiency of 8.22%, which result from synergetic improvements of light harvesting, charge carrier transport and collection, and morphology. The results indicate that rational design of novel donor materials is important for non-fullerene organic solar cells.
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Affiliation(s)
- Tao Liu
- Heeger Beijing Research and Development CenterSchool of Chemistry and EnvironmentBeihang UniversityBeijing100191P. R. China
| | - Dong Meng
- Beijing National Laboratory for Molecular ScienceKey Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
| | - Yunhao Cai
- Heeger Beijing Research and Development CenterSchool of Chemistry and EnvironmentBeihang UniversityBeijing100191P. R. China
| | - Xiaobo Sun
- Heeger Beijing Research and Development CenterSchool of Chemistry and EnvironmentBeihang UniversityBeijing100191P. R. China
| | - Yan Li
- Beijing National Laboratory for Molecular ScienceKey Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
| | - Lijun Huo
- Heeger Beijing Research and Development CenterSchool of Chemistry and EnvironmentBeihang UniversityBeijing100191P. R. China
| | - Feng Liu
- Materials Science DivisionLawrence Berkeley National LabBerkeleyCA94720USA
| | - Zhaohui Wang
- Beijing National Laboratory for Molecular ScienceKey Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
| | - Thomas P. Russell
- Polymer Science and Engineering DepartmentUniversity of MassachusettsAmherstMA01003USA
| | - Yanming Sun
- Heeger Beijing Research and Development CenterSchool of Chemistry and EnvironmentBeihang UniversityBeijing100191P. R. China
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41
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Analysis of Triplet Exciton Loss Pathways in PTB7:PC71BM Bulk Heterojunction Solar Cells. Sci Rep 2016; 6:29158. [PMID: 27380928 PMCID: PMC4933975 DOI: 10.1038/srep29158] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 06/15/2016] [Indexed: 02/03/2023] Open
Abstract
A strategy for increasing the conversion efficiency of organic photovoltaics has been to increase the VOC by tuning the energy levels of donor and acceptor components. However, this opens up a new loss pathway from an interfacial charge transfer state to a triplet exciton (TE) state called electron back transfer (EBT), which is detrimental to device performance. To test this hypothesis, we study triplet formation in the high performing PTB7:PC71BM blend system and determine the impact of the morphology-optimizing additive 1,8-diiodoctane (DIO). Using photoluminescence and spin-sensitive optically detected magnetic resonance (ODMR) measurements at low temperature, we find that TEs form on PC71BM via intersystem crossing from singlet excitons and on PTB7 via EBT mechanism. For DIO blends with smaller fullerene domains, an increased density of PTB7 TEs is observed. The EBT process is found to be significant only at very low temperature. At 300 K, no triplets are detected via ODMR, and electrically detected magnetic resonance on optimized solar cells indicates that TEs are only present on the fullerenes. We conclude that in PTB7:PC71BM devices, TE formation via EBT is impacted by fullerene domain size at low temperature, but at room temperature, EBT does not represent a dominant loss pathway.
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42
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Affiliation(s)
- Svante Hedström
- Department of Chemistry, Division of Theoretical Chemistry, Lund University , Lund, Sweden
- Department of Chemistry, Yale University , New Haven, CT, USA
| | - Ergang Wang
- Department of Chemical and Biological Engineering/Polymer Technology, Chalmers University of Technology , Gothenburg, Sweden
| | - Petter Persson
- Department of Chemistry, Division of Theoretical Chemistry, Lund University , Lund, Sweden
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43
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Travis W, Knapp CE, Savory CN, Ganose AM, Kafourou P, Song X, Sharif Z, Cockcroft JK, Scanlon DO, Bronstein H, Palgrave RG. Hybrid Organic–Inorganic Coordination Complexes as Tunable Optical Response Materials. Inorg Chem 2016; 55:3393-400. [DOI: 10.1021/acs.inorgchem.5b02749] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | - Alex M. Ganose
- Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | | | | | | | | | - David O. Scanlon
- Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
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44
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Scharber MC. On the Efficiency Limit of Conjugated Polymer:Fullerene-Based Bulk Heterojunction Solar Cells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:1994-2001. [PMID: 26757236 DOI: 10.1002/adma.201504914] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 11/22/2015] [Indexed: 05/20/2023]
Abstract
The power conversion efficiency potential of eight high-performance polymer-fullerene blends is investigated. All studied absorbers show the typical organic solar cell losses limiting their performance to ≈13%.
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Affiliation(s)
- Markus C Scharber
- Linz Institute for Organic Solar Cells, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040, Linz, Austria
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45
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Liu F, Fan H, Zhang Z, Zhu X. Low-Bandgap Small-Molecule Donor Material Containing Thieno[3,4-b]thiophene Moiety for High-Performance Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2016; 8:3661-3668. [PMID: 26512794 DOI: 10.1021/acsami.5b08121] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
By replacing the central thiophene of STDR, a sepithiophene terminated with two 3-ethylrhodanine moieties, with 2-ethylhexyl 3-fluorothieno[3,4-b]thiophene-2-carboxylate, an A-D-Q-D-A-type small molecule has been developed for high-performance organic solar cells with improved photocurrent. STDR-TbT exhibits a significant bathochromic shift with a low optical bandgap of approximately 1.60 eV in the thin film. Accordingly, STDR-TbT shows broad external quantum efficiency spectral response up to 800 nm. A high short circuit current (Jsc) of 10.90 mA cm(-2) was achieved for STDR-TbT:PC71BM-based devices; this is significantly higher than that of STDR:PC71BM-based devices, Jsc: 5.61 mA cm(-2), with a power-conversion efficiency (PCE) of 5.05%. Compared with STDR-based devices, STDR-TbT-based devices show balanced charge carrier transport, better thin-film morphology, and favorable charge separation/collection.
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Affiliation(s)
- Feng Liu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, P. R. China
| | - Haijun Fan
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, P. R. China
| | - Zhiguo Zhang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, P. R. China
| | - Xiaozhang Zhu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, P. R. China
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46
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Roy P, Jha A, Dasgupta J. Photoinduced charge generation rates in soluble P3HT : PCBM nano-aggregates predict the solvent-dependent film morphology. NANOSCALE 2016; 8:2768-2777. [PMID: 26763690 DOI: 10.1039/c5nr06445g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The device efficiency of bulk heterojunction (BHJ) solar cells is critically dependent on the nano-morphology of the solution-processed polymer : fullerene blend. Active control on blend morphology can only emanate from a detailed understanding of solution structures during the film casting process. Here we use photoinduced charge transfer (CT) rates to probe the effective length scale of the pre-formed solution structures and their energy disorder arising from a mixture of poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) in three different organic solvents. The observed solvent-dependent ultrafast biphasic rise of the transient polaron state in solution along with changes detected in the C=C stretching frequency of bound PCBM provides direct evidence for film-like P3HT : PCBM interfaces in solution. Using the diffusive component of the charge transfer rate, we deduce ∼3-times larger functional nano-domain size in toluene than in chlorobenzene thereby correctly predicting the relative polymer nanofiber widths observed in annealed films. We thus provide first experimental evidence for the postulated polymer : fullerene : solvent ternary phase that seeds the eventual morphology in spin-cast films. Our work motivates the design of new chemical additives to tune the grain size of the evolving polymer : fullerene domains within the solution phase.
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Affiliation(s)
- Palas Roy
- Department of Chemical Sciences, 1 Homi Bhabha Road, Tata Institute of Fundamental Research, Mumbai 400005, India.
| | - Ajay Jha
- Department of Chemical Sciences, 1 Homi Bhabha Road, Tata Institute of Fundamental Research, Mumbai 400005, India.
| | - Jyotishman Dasgupta
- Department of Chemical Sciences, 1 Homi Bhabha Road, Tata Institute of Fundamental Research, Mumbai 400005, India.
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47
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Hwang YJ, Li H, Courtright BAE, Subramaniyan S, Jenekhe SA. Nonfullerene Polymer Solar Cells with 8.5% Efficiency Enabled by a New Highly Twisted Electron Acceptor Dimer. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:124-131. [PMID: 26513532 DOI: 10.1002/adma.201503801] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 09/16/2015] [Indexed: 06/05/2023]
Abstract
Fullerene-free and processing additive-free 8.5% efficient polymer solar cells are achieved by using a new 3,4-ethylenedioxythiophene-linked arylene diimide dimer with a 76° twist angle. The devices combine high (78-83%) external quantum efficiency with high (0.91-0.95 V) photovoltages and thus have relatively low optical bandgap energy loss.
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Affiliation(s)
- Ye-Jin Hwang
- Department of Chemical Engineering and Department of Chemistry, University of Washington, Seattle, WA, 98195-1750, USA
| | - Haiyan Li
- Department of Chemical Engineering and Department of Chemistry, University of Washington, Seattle, WA, 98195-1750, USA
| | - Brett A E Courtright
- Department of Chemical Engineering and Department of Chemistry, University of Washington, Seattle, WA, 98195-1750, USA
| | - Selvam Subramaniyan
- Department of Chemical Engineering and Department of Chemistry, University of Washington, Seattle, WA, 98195-1750, USA
| | - Samson A Jenekhe
- Department of Chemical Engineering and Department of Chemistry, University of Washington, Seattle, WA, 98195-1750, USA
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48
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Li-Destri G, Tummino A, Malfatti Gasperini AA, Parellada Monreal L, Messina GML, Spampinato V, Ceccone G, Konovalov O. Filling nanoporous polymer thin films: an easy route toward the full control of the 3D nanostructure. RSC Adv 2016. [DOI: 10.1039/c5ra26053a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A fully controllable interpenetrated 3D nanostructure is obtained by filling a nanoporous polymer ultrathin film with a second organic component.
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Affiliation(s)
| | - A. Tummino
- ESRF-The European Synchrotron
- Grenoble
- France
- Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN)
- Department of Chemistry
| | | | | | - G. M. L. Messina
- Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN)
- Department of Chemistry
- University of Catania and CSGI
- 95125 Catania
- Italy
| | - V. Spampinato
- European Commission, Joint Research Centre
- Institute for Health and Consumer Protection
- Ispra
- Italy
| | - G. Ceccone
- European Commission, Joint Research Centre
- Institute for Health and Consumer Protection
- Ispra
- Italy
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49
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Rudenko AE, Khlyabich PP, Thompson BC. Random poly(3‐hexylthiophene‐
co
‐3‐cyanothiophene‐
co
‐3‐(2‐ethylhexyl)thiophene) copolymers with high open‐circuit voltage in polymer solar cells. ACTA ACUST UNITED AC 2015. [DOI: 10.1002/pola.28007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Andrey E. Rudenko
- Department of Chemistry and Loker Hydrocarbon Research InstituteUniversity of Southern CaliforniaLos Angeles California90089‐1661
| | - Petr P. Khlyabich
- Department of Chemistry and Loker Hydrocarbon Research InstituteUniversity of Southern CaliforniaLos Angeles California90089‐1661
| | - Barry C. Thompson
- Department of Chemistry and Loker Hydrocarbon Research InstituteUniversity of Southern CaliforniaLos Angeles California90089‐1661
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50
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Armaroli N, Balzani V. Solar Electricity and Solar Fuels: Status and Perspectives in the Context of the Energy Transition. Chemistry 2015; 22:32-57. [PMID: 26584653 DOI: 10.1002/chem.201503580] [Citation(s) in RCA: 254] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Indexed: 11/07/2022]
Abstract
The energy transition from fossil fuels to renewables is already ongoing, but it will be a long and difficult process because the energy system is a gigantic and complex machine. Key renewable energy production data show the remarkable growth of solar electricity technologies and indicate that crystalline silicon photovoltaics (PV) and wind turbines are the workhorses of the first wave of renewable energy deployment on the TW scale around the globe. The other PV alternatives (e.g., copper/indium/gallium/selenide (CIGS) or CdTe), along with other less mature options, are critically analyzed. As far as fuels are concerned, the situation is significantly more complex because making chemicals with sunshine is far more complicated than generating electric current. The prime solar artificial fuel is molecular hydrogen, which is characterized by an excellent combination of chemical and physical properties. The routes to make it from solar energy (photoelectrochemical cells (PEC), dye-sensitized photoelectrochemical cells (DSPEC), PV electrolyzers) and then synthetic liquid fuels are presented, with discussion on economic aspects. The interconversion between electricity and hydrogen, two energy carriers directly produced by sunlight, will be a key tool to distribute renewable energies with the highest flexibility. The discussion takes into account two concepts that are often overlooked: the energy return on investment (EROI) and the limited availability of natural resources-particularly minerals-which are needed to manufacture energy converters and storage devices on a multi-TW scale.
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Affiliation(s)
- Nicola Armaroli
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Via Gobetti 101, 40129 Bologna (Italy), Fax: (+39) 051-6399844.
| | - Vincenzo Balzani
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, Via Selmi 2, 40126 Bologna (Italy), Fax: (+39) 051-2099456.
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