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A Comparative Study of the Effect of Graphene Oxide, Graphitic Carbon Nitride, and Their Composite on the Photocatalytic Activity of Cu3SnS4. Catalysts 2021. [DOI: 10.3390/catal12010014] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Photocatalysis has shown high potential in dealing with the ever-broadening problem of wastewater treatment, escalated by the increasing level of recalcitrant chemicals often referred to as emerging contaminants. In this study, the effect of support material on the photocatalytic activity of copper tin sulfide (Cu3SnS4) nanoparticles for the degradation of tetracycline as an emerging contaminant is presented. Graphene oxide, protonated graphitic carbon nitride, and a composite of graphitic carbon nitride and graphene oxide were explored as support materials for Cu3SnS4 nanoparticles. The nanoparticles were incorporated with the different carbonaceous substrates to afford graphene-supported Cu3SnS4 (GO-CTS), protonated graphitic carbon nitride-supported Cu3SnS4 (PCN-CTS), and graphene oxide/protonated graphitic carbon nitride-supported Cu3SnS4 (GO/PCN-CTS). Physicochemical, structural, and optical properties of the prepared nanocomposites were characterized using techniques such as Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis near infrared, and fluorescence spectrophotometry. The compositing of the Cu3SnS4 nanoparticles on the support materials was confirmed by the characterization techniques, and the optical properties of the composites were found to be influenced by the nature of the support material. The incorporation of CTS into the support materials resulted in a reduction in band gap energy with evaluated band gaps of 1.65, 1.46, 1.43 eV, and 1.16 eV. The reduction in band gap energy suggests the potential of the composites for enhanced photocatalytic activity. From the photocatalytic study, the degradation efficiency of tetracycline by CTS, PCN-CTS, GO-CTS, and PC/GO-CTS was 74.1, 85.2, 90.9, and 96.5%, respectively. All the composites showed enhanced activity compared to pristine CTS, and the existence of a synergy between GO and PCN when both were employed as support materials was observed. Based on the charge carrier recombination characteristics and the band edge potential calculations from the composites, a possible mechanism of action of each composite was proposed. This study therefore confirms the possibility of modulating the mechanism of action and subsequently the efficiency of semiconductor materials by altering the nature of the support material.
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2
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Wang L, Zhang L, Jiang Y, Li P, Li J, Li X. Theoretical investigation of selected hydrogenated germanium clusters (Ge5Hn, n = 0–12) from density functional theory calculations. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1657193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Liuchang Wang
- School of Chemical Engineering, Xi’an University, Xi’an, People’s Republic of China
| | - Lu Zhang
- School of Chemical Engineering, Xi’an University, Xi’an, People’s Republic of China
| | - Yong Jiang
- School of Chemical Engineering, Xi’an University, Xi’an, People’s Republic of China
| | - Pengna Li
- School of Chemical Engineering, Xi’an University, Xi’an, People’s Republic of China
| | - Jiangtao Li
- School of Chemical Engineering, Xi’an University, Xi’an, People’s Republic of China
| | - Xiaojun Li
- School of Chemical Engineering, Xi’an University, Xi’an, People’s Republic of China
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3
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Gordi M, Moravvej-Farshi MK, Ramezani H. Effects of Electric Fields on Multiple Exciton Generation. Chemphyschem 2018; 19:2782-2787. [PMID: 29993169 DOI: 10.1002/cphc.201800400] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Indexed: 11/06/2022]
Abstract
Unique properties of lead chalcogenides have enabled multiple exciton generation (MEG) in their nanocrystals that can be beneficial in enhancing the efficiency of third-generation solar cells. Although the intrinsic electric field plays an imperative role in a solar cell, its effect on the multiple exciton generation (MEG) has been overlooked, so far. Using EOM-CCSD as a many-body approach, we show that any electric field can affect the absorptivity spectra of the lead chalcogenide nanocrystals (Pb4 Te4 , Pb4 Se4 , and Pb4 S4 ). The same electric field, however, has insignificant effects on the MEG quantum probabilities and the thresholds in these nanocrystals. Furthermore, simulations show that Pb4 Te4 , among the aforementioned nanocrystals, has the lowest MEG threshold and the strongest absorptivity peak that is located in the multi-excitation window, irrespective of the field strength, making it the most suitable candidate for MEG applications. Simulations also demonstrate that an electric field affects the MEG characteristics in the Pb4 Te4 nanocrystal, in general, less than it perturbs MEG characteristics in Pb4 Se4 and Pb4 S4 nanocrystals. Our results can have a great impact in designing optoelectronic devices whose performance can be significantly influenced by MEG.
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Affiliation(s)
- Mahdi Gordi
- University of Tarbiat Modares, Faculty of Electrical and Computer Engineering, Nano Plasmo-photonic Research Group, P. O. Box 14115-194, Tehran, 1411713116, Iran
| | - Mohammad Kazem Moravvej-Farshi
- University of Tarbiat Modares, Faculty of Electrical and Computer Engineering, Nano Plasmo-photonic Research Group, P. O. Box 14115-194, Tehran, 1411713116, Iran
| | - Hamidreza Ramezani
- University of Texas Rio Grande Valley, Department of Physics and Astronomy, Brownsville, TX 78520, USA
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4
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Hetzer C, Guldi DM, Tykwinski RR. Pentacene Dimers as a Critical Tool for the Investigation of Intramolecular Singlet Fission. Chemistry 2018; 24:8245-8257. [DOI: 10.1002/chem.201705355] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Constantin Hetzer
- Department of Chemistry and Pharmacy; Interdisciplinary Center for Molecular Materials (ICMM); Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Nikolaus-Fiebiger-Straße 10 91058 Erlangen Germany
| | - Dirk M. Guldi
- Department of Chemistry and Pharmacy; Interdisciplinary Center for Molecular Materials (ICMM); Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Egerlandstrasse 3 91058 Erlangen Germany
| | - Rik R. Tykwinski
- Department of Chemistry; University of Alberta; Edmonton Alberta T6G 2G2 Canada
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5
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Liu XY, Xie XY, Fang WH, Cui G. Photoinduced relaxation dynamics of nitrogen-capped silicon nanoclusters: a TD-DFT study. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1433335] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Xiang-Yang Liu
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Xiao-Ying Xie
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
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6
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Li X, Yan Z, Li S. The nature of structure and bonding between transition metal and mixed Si-Ge tetramers: A 20-electron superatom system. J Comput Chem 2016; 37:2316-23. [PMID: 27452479 DOI: 10.1002/jcc.24456] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/28/2016] [Accepted: 07/04/2016] [Indexed: 01/16/2023]
Abstract
A novel superatom species with 20-electron system, Six Gey M(+) (x + y = 4; M = Nb, Ta), was properly proposed. The trigonal bipyramid structures for the studied systems were identified as the putative global minimum by means of the density functional theory calculations. The high chemical stability can be explained by the strong p-d hybridization between transition metal and mixed Si-Ge tetramers, and closed-shell valence electron configuration [1S(2) 1P(6) 2S(2) 1D(10) ]. Meanwhile, the chemical bondings between metal atom and the tetramers can be recognized by three localized two-center two-electron (2c-2e) and delocalized 3c-2e σ-bonds. For all the doped structures studied here, it was found that the π- and σ-electrons satisfy the 2(N + 1)(2) counting rule, and thus these clusters possess spherically double (π and σ) aromaticity, which is also confirmed by the negative nucleus-independent chemical shifts values. Consequently, all the calculated results provide a further understanding for structural stabilities and electronic properties of transition metal-doped semiconductor clusters. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Xiaojun Li
- The Key Laboratory for Surface Engineering and Remanufacturing in Shaanxi Province, School of Chemical Engineering, Xi'an University, Xi'an, Shaanxi, 710065, China
| | - Zhijun Yan
- The Key Laboratory for Surface Engineering and Remanufacturing in Shaanxi Province, School of Chemical Engineering, Xi'an University, Xi'an, Shaanxi, 710065, China
| | - Shuna Li
- The Key Laboratory for Surface Engineering and Remanufacturing in Shaanxi Province, School of Chemical Engineering, Xi'an University, Xi'an, Shaanxi, 710065, China
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7
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Pal S, Trivedi DJ, Akimov AV, Aradi B, Frauenheim T, Prezhdo OV. Nonadiabatic Molecular Dynamics for Thousand Atom Systems: A Tight-Binding Approach toward PYXAID. J Chem Theory Comput 2016; 12:1436-48. [DOI: 10.1021/acs.jctc.5b01231] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sougata Pal
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Dhara J. Trivedi
- Department
of Physics and Astronomy, University of Rochester, Rochester, New York 14627, United States
| | - Alexey V. Akimov
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, United States
| | - Bálint Aradi
- Bremen
Center for Computational Materials Science, Universität Bremen, Otto-Hahn-Alle 1, 28359 Bremen, Germany
| | - Thomas Frauenheim
- Bremen
Center for Computational Materials Science, Universität Bremen, Otto-Hahn-Alle 1, 28359 Bremen, Germany
| | - Oleg V. Prezhdo
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
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8
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Fernando A, Weerawardene KLDM, Karimova NV, Aikens CM. Quantum Mechanical Studies of Large Metal, Metal Oxide, and Metal Chalcogenide Nanoparticles and Clusters. Chem Rev 2015; 115:6112-216. [PMID: 25898274 DOI: 10.1021/cr500506r] [Citation(s) in RCA: 217] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Amendra Fernando
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
| | | | - Natalia V Karimova
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
| | - Christine M Aikens
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
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9
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Baxter JB, Richter C, Schmuttenmaer CA. Ultrafast Carrier Dynamics in Nanostructures for Solar Fuels. Annu Rev Phys Chem 2014; 65:423-47. [DOI: 10.1146/annurev-physchem-040513-103742] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Sunlight can be used to drive chemical reactions to produce fuels that store energy in chemical bonds. These fuels, such as hydrogen from splitting water, have much larger energy density than do electrical storage devices. The efficient conversion of clean, sustainable solar energy using photoelectrochemical and photocatalytic systems requires precise control over the thermodynamics, kinetics, and structural aspects of materials and molecules. Generation, thermalization, trapping, interfacial transfer, and recombination of photoexcited charge carriers often occur on femtosecond to picosecond timescales. These short timescales limit the transport of photoexcited carriers to nanometer-scale distances, but nanostructures with high surface-to-volume ratios can enable both significant light absorption and high quantum efficiency. This review highlights the importance of understanding ultrafast carrier dynamics for the generation of solar fuels, including case studies on colloidal nanostructures, nanostructured photoelectrodes, and photoelectrodes sensitized with molecular chromophores and catalysts.
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Affiliation(s)
- Jason B. Baxter
- Drexel University, Department of Chemical and Biological Engineering, Philadelphia, Pennsylvania 19104
| | - Christiaan Richter
- Rochester Institute of Technology, Department of Chemical Engineering, Rochester, New York 14623
| | - Charles A. Schmuttenmaer
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107
- Energy Sciences Institute, Yale University, West Haven, Connecticut 06516-7394
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11
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Akimov AV, Prezhdo OV. Nonadiabatic Dynamics of Charge Transfer and Singlet Fission at the Pentacene/C60 Interface. J Am Chem Soc 2014; 136:1599-608. [DOI: 10.1021/ja411800n] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Alexey V. Akimov
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
- Department
of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Oleg V. Prezhdo
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
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12
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Hyeon-Deuk K, Kobayashi Y, Tamai N. Evidence of Phonon-Assisted Auger Recombination and Multiple Exciton Generation in Semiconductor Quantum Dots Revealed by Temperature-Dependent Phonon Dynamics. J Phys Chem Lett 2014; 5:99-105. [PMID: 26276187 DOI: 10.1021/jz402305r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Auger processes, multiple exciton generation, and Auger recombination, provide and disturb a potential route to increase solar cell efficiencies by creating multiple charge carriers, respectively. Physical mechanisms of the Auger processes can be deduced from the temperature dependence. Our real-time ab initio simulation found logarithmic temperature dependence of the Auger rates in semiconductor quantum dots (QDs), which agrees well with the recent experimental observations. This anomalous temperature dependence is not only determined by static electronic structures of the QDs depending on temperature, but also attributed to dynamical electron-phonon couplings, directly demonstrating that the Auger processes are actually induced by the electron-phonon couplings and can be controlled by phonon modes. Our findings suggest that high-frequency and broad phonon modes of a QD including the surface ligands dictate efficient Auger dynamics in a QD.
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Affiliation(s)
- Kim Hyeon-Deuk
- Department of Chemistry, Kyoto University, Kyoto, 606-8502, Japan
- Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
- Department of Chemistry, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara-shi, Kanagawa, 252-5258, Japan
- Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo, 669-1337, Japan
| | - Yoichi Kobayashi
- Department of Chemistry, Kyoto University, Kyoto, 606-8502, Japan
- Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
- Department of Chemistry, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara-shi, Kanagawa, 252-5258, Japan
- Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo, 669-1337, Japan
| | - Naoto Tamai
- Department of Chemistry, Kyoto University, Kyoto, 606-8502, Japan
- Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
- Department of Chemistry, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara-shi, Kanagawa, 252-5258, Japan
- Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo, 669-1337, Japan
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13
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Makowska-Janusik M, Kityk IV, Myronchuk G, Zamuraeva O, Parasyuk OV. Manifestation of intrinsic defects in the band structures of quaternary chalcogenide Ag2In2SiSe6 and Ag2In2GeSe6 crystals. CrystEngComm 2014. [DOI: 10.1039/c4ce01005a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Complex studies on the band structures of novel Ag2In2SiSe6 and Ag2In2GeSe6 crystals were performed.
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Affiliation(s)
| | - I. V. Kityk
- Faculty of Electrical Engineering
- Czestochowa University of Technology
- 42-200 Czestochowa, Poland
| | - G. Myronchuk
- Physical Faculty
- Eastern European University
- Lutsk, Ukraine
| | - O. Zamuraeva
- Physical Faculty
- Eastern European University
- Lutsk, Ukraine
| | - O. V. Parasyuk
- Physical Faculty
- Eastern European University
- Lutsk, Ukraine
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14
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Li R, Zhang J, Xu Y, Miao X, Zhang D. Electronic transport behaviours of lead chalcogenide (PbE) n (E = S and Se) nanocluster junctions by ab initio simulation. RSC Adv 2014. [DOI: 10.1039/c4ra00033a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
All investigated (PbS)n and (PbSe)n nanocluster-based molecular junctions show metallic behavior at low biases (−2 V, 2 V) while negative differential resistance (NDR) appears at a certain high bias range.
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Affiliation(s)
- Rong Li
- School of Optical and Electronic Information
- Huazhong University of Science and Technology
- Wuhan City, P. R. China
| | - Jianbing Zhang
- School of Optical and Electronic Information
- Huazhong University of Science and Technology
- Wuhan City, P. R. China
- Wuhan National Laboratory for Optoelectronics
- Wuhan City, P. R. China
| | - Yuanlan Xu
- School of Optical and Electronic Information
- Huazhong University of Science and Technology
- Wuhan City, P. R. China
| | - Xiangshui Miao
- School of Optical and Electronic Information
- Huazhong University of Science and Technology
- Wuhan City, P. R. China
- Wuhan National Laboratory for Optoelectronics
- Wuhan City, P. R. China
| | - Daoli Zhang
- School of Optical and Electronic Information
- Huazhong University of Science and Technology
- Wuhan City, P. R. China
- Wuhan National Laboratory for Optoelectronics
- Wuhan City, P. R. China
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15
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Liu J, Neukirch AJ, Prezhdo OV. Phonon-induced pure-dephasing of luminescence, multiple exciton generation, and fission in silicon clusters. J Chem Phys 2013; 139:164303. [DOI: 10.1063/1.4825401] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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16
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Jaeger HM, Hyeon-Deuk K, Prezhdo OV. Exciton multiplication from first principles. Acc Chem Res 2013; 46:1280-9. [PMID: 23459543 DOI: 10.1021/ar3002365] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Third-generation photovolatics require demanding cost and power conversion efficiency standards, which may be achieved through efficient exciton multiplication. Therefore, generating more than one electron-hole pair from the absorption of a single photon has vast ramifications on solar power conversion technology. Unlike their bulk counterparts, irradiated semiconductor quantum dots exhibit efficient exciton multiplication, due to confinement-enhanced Coulomb interactions and slower nonradiative losses. The exact characterization of the complicated photoexcited processes within quantum-dot photovoltaics is a work in progress. In this Account, we focus on the photophysics of nanocrystals and investigate three constituent processes of exciton multiplication, including photoexcitation, phonon-induced dephasing, and impact ionization. We quantify the role of each process in exciton multiplication through ab initio computation and analysis of many-electron wave functions. The probability of observing a multiple exciton in a photoexcited state is proportional to the magnitude of electron correlation, where correlated electrons can be simultaneously promoted across the band gap. Energies of multiple excitons are determined directly from the excited state wave functions, defining the threshold for multiple exciton generation. This threshold is strongly perturbed in the presence of surface defects, dopants, and ionization. Within a few femtoseconds following photoexcitation, the quantum state loses coherence through interactions with the vibrating atomic lattice. The phase relationship between single excitons and multiple excitons dissipates first, followed by multiple exciton fission. Single excitons are coupled to multiple excitons through Coulomb and electron-phonon interactions, and as a consequence, single excitons convert to multiple excitons and vice versa. Here, exciton multiplication depends on the initial energy and coupling magnitude and competes with electron-phonon energy relaxation. Multiple excitons are generated through impact ionization within picoseconds. The basis of exciton multiplication in quantum dots is the collective result of photoexcitation, dephasing, and nonadiabatic evolution. Each process is characterized by a distinct time-scale, and the overall multiple exciton generation dynamics is complete by about 10 ps. Without relying on semiempirical parameters, we computed quantum mechanical probabilities of multiple excitons for small model systems. Because exciton correlations and coherences are microscopic, quantum properties, results for small model systems can be extrapolated to larger, realistic quantum dots.
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Affiliation(s)
- Heather M. Jaeger
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Kim Hyeon-Deuk
- Department of Chemistry, Kyoto University, 606-8502, Kyoto, Japan
| | - Oleg V. Prezhdo
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
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17
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Kanal IY, Owens SG, Bechtel JS, Hutchison GR. Efficient Computational Screening of Organic Polymer Photovoltaics. J Phys Chem Lett 2013; 4:1613-1623. [PMID: 26282968 DOI: 10.1021/jz400215j] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
There has been increasing interest in rational, computationally driven design methods for materials, including organic photovoltaics (OPVs). Our approach focuses on a screening "pipeline", using a genetic algorithm for first stage screening and multiple filtering stages for further refinement. An important step forward is to expand our diversity of candidate compounds, including both synthetic and property-based measures of diversity. For example, top monomer pairs from our screening are all donor-donor (D-D) combinations, in contrast with the typical donor-acceptor (D-A) motif used in organic photovoltaics. We also find a strong "sequence effect", in which the average HOMO-LUMO gap of tetramers changes by ∼0.2 eV as a function of monomer sequence (e.g., ABBA versus BAAB); this has rarely been explored in conjugated polymers. Beyond such optoelectronic optimization, we discuss other properties needed for high-efficiency organic solar cells, and applications of screening methods to other areas, including non-fullerene n-type materials, tandem cells, and improving charge and exciton transport.
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Affiliation(s)
- Ilana Y Kanal
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Steven G Owens
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Jonathon S Bechtel
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Geoffrey R Hutchison
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
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18
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Bao W, Melli M, Caselli N, Riboli F, Wiersma DS, Staffaroni M, Choo H, Ogletree DF, Aloni S, Bokor J, Cabrini S, Intonti F, Salmeron MB, Yablonovitch E, Schuck PJ, Weber-Bargioni A. Mapping Local Charge Recombination Heterogeneity by Multidimensional Nanospectroscopic Imaging. Science 2012; 338:1317-21. [DOI: 10.1126/science.1227977] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Wei Bao
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA 94720, USA
| | - M. Melli
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - N. Caselli
- European Laboratory for Non-Linear Spectroscopy, 50019 Sesto Fiorentino, Firenze, Italy
- Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Firenze, Italy
| | - F. Riboli
- European Laboratory for Non-Linear Spectroscopy, 50019 Sesto Fiorentino, Firenze, Italy
- Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Firenze, Italy
| | - D. S. Wiersma
- European Laboratory for Non-Linear Spectroscopy, 50019 Sesto Fiorentino, Firenze, Italy
- Istituto Nazionale di Ottica (CNR-INO), 50125 Firenze, Italy
| | - M. Staffaroni
- Department of Electrical Engineering and Computer Sciences, University of California Berkeley, Berkeley, CA 94720–1770, USA
| | - H. Choo
- Department of Electrical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - D. F. Ogletree
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - S. Aloni
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - J. Bokor
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Electrical Engineering and Computer Sciences, University of California Berkeley, Berkeley, CA 94720–1770, USA
| | - S. Cabrini
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - F. Intonti
- European Laboratory for Non-Linear Spectroscopy, 50019 Sesto Fiorentino, Firenze, Italy
- Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Firenze, Italy
| | - M. B. Salmeron
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA 94720, USA
| | - E. Yablonovitch
- Department of Electrical Engineering and Computer Sciences, University of California Berkeley, Berkeley, CA 94720–1770, USA
| | - P. J. Schuck
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - A. Weber-Bargioni
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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Hyeon-Deuk K, Prezhdo OV. Photoexcited electron and hole dynamics in semiconductor quantum dots: phonon-induced relaxation, dephasing, multiple exciton generation and recombination. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:363201. [PMID: 22906924 DOI: 10.1088/0953-8984/24/36/363201] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Photoexcited dynamics of electrons and holes in semiconductor quantum dots (QD), including phonon-induced relaxation, multiple exciton generation, fission and recombination (MEG, MEF and MER), were simulated by combining ab initio time-dependent density functional theory and non-adiabatic molecular dynamics. These nonequilibrium phenomena govern the optical properties and photoexcited dynamics of QDs, determining the branching between electronic processes and thermal energy losses. Our approach accounts for QD size and shape as well as defects, core-shell distribution, surface ligands and charge trapping, which significantly influence the properties of photoexcited QDs. The method creates an explicit time-domain representation of photoinduced processes and describes various kinetic regimes owing to the non-perturbative treatment of quantum dynamics. QDs of different sizes and materials, with and without ligands, are considered. The simulations provide direct evidence that the high-frequency ligand modes on the QD surface play a pivotal role in the electron-phonon relaxation, MEG, MEF and MER. The insights reported here suggest novel routes for controlling the photoinduced processes in semiconductor QDs and lead to new design principles for increasing the efficiencies of photovoltaic devices.
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Affiliation(s)
- Kim Hyeon-Deuk
- Department of Chemistry, Kyoto University, Kyoto, 606-8502, Japan.
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Hyeon-Deuk K, Prezhdo OV. Multiple exciton generation and recombination dynamics in small Si and CdSe quantum dots: an ab initio time-domain study. ACS NANO 2012; 6:1239-1250. [PMID: 22214339 DOI: 10.1021/nn2038884] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Multiple exciton generation and recombination (MEG and MER) dynamics in semiconductor quantum dots (QDs) are simulated using ab initio time-dependent density functional theory in combination with nonadiabatic molecular dynamics. The approach differs from other MEG and MER theories because it provides atomistic description, employs time-domain representation, allows for various dynamical regimes, and includes electron-phonon interactions. MEG rapidly accelerates with energy, reflecting strong energy dependence of double exciton (DE) density of states. At early times, MEG is Gaussian rather than exponential. Exponential dynamics, assumed in rate theories, starts at a later time and becomes more important in larger QDs. Phonon-assisted MEG is observed at energies below the purely electronic threshold, particularly in the presence of high-frequency ligand vibrations. Coupling to phonons is essential for MER since higher-energy DEs must relax to recombine into single excitons (SEs), and SEs formed during MERs must lose some of their energy to avoid recreating DEs. MER simulated starting from a DE is significantly slower than MER involving an optical excitation of a SE, followed by MEG and then MER. The latter time scale agrees with experiment, emphasizing the importance of quantum-mechanical superpositions of many DEs for efficient MER. The detailed description of the interplay between MEG and MER coupled to phonons provides important insights into the excited state dynamics of semiconductor QDs and nanoscale materials in general.
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Affiliation(s)
- Kim Hyeon-Deuk
- Department of Chemistry, Kyoto University, Kyoto 606-8502, Japan.
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Long R, Prezhdo OV. Ab Initio Nonadiabatic Molecular Dynamics of the Ultrafast Electron Injection from a PbSe Quantum Dot into the TiO2 Surface. J Am Chem Soc 2011; 133:19240-9. [DOI: 10.1021/ja2085806] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Run Long
- Department of Chemistry, University of Rochester, New York 14627, United States
- School of Chemical & Bioprocess Engineering, University College Dublin, Ireland
| | - Oleg V. Prezhdo
- Department of Chemistry, University of Rochester, New York 14627, United States
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Hyeon-Deuk K, Prezhdo OV. Time-domain ab initio study of Auger and phonon-assisted auger processes in a semiconductor quantum dot. NANO LETTERS 2011; 11:1845-1850. [PMID: 21452839 DOI: 10.1021/nl200651p] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We developed time-domain ab initio simulation of Auger phenomena, including multiple exciton generation (MEG) and recombination (MER). It is the first approach describing phonon-assisted processes and early dynamics. MEG starts below the electronic threshold, strongly accelerating with energy. Ligands are particularly important to phonon-assisted MEG, which therefore can be probed with infrared spectroscopy. Short-time gaussian component gives 5-10% of MEG, justifying rate theories that assume exponential dynamics. MER is preceded by electron-phonon relaxation to low energies.
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Affiliation(s)
- Kim Hyeon-Deuk
- Department of Chemistry, Kyoto University, Kyoto, 606-8502, Japan.
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