1
|
Hahn RVH, Rodríguez-Bolívar S, Rodosthenous P, Skibinsky-Gitlin ES, Califano M, Gómez-Campos FM. Optical Absorption in N-Dimensional Colloidal Quantum Dot Arrays: Influence of Stoichiometry and Applications in Intermediate Band Solar Cells. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3387. [PMID: 36234515 PMCID: PMC9565355 DOI: 10.3390/nano12193387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/21/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
We present a theoretical atomistic study of the optical properties of non-toxic InX (X = P, As, Sb) colloidal quantum dot arrays for application in photovoltaics. We focus on the electronic structure and optical absorption and on their dependence on array dimensionality and surface stoichiometry motivated by the rapid development of experimental techniques to achieve high periodicity and colloidal quantum dot characteristics. The homogeneous response of colloidal quantum dot arrays to different light polarizations is also investigated. Our results shed light on the optical behaviour of these novel multi-dimensional nanomaterials and identify some of them as ideal building blocks for intermediate band solar cells.
Collapse
Affiliation(s)
- Rebeca V. H. Hahn
- Departamento de Electrónica y Tecnología de los Computadores, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Salvador Rodríguez-Bolívar
- Departamento de Electrónica y Tecnología de los Computadores, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Panagiotis Rodosthenous
- Pollard Institute, School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, UK
| | - Erik S. Skibinsky-Gitlin
- Departamento de Electrónica y Tecnología de los Computadores, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Marco Califano
- Pollard Institute, School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, UK
| | - Francisco M. Gómez-Campos
- Departamento de Electrónica y Tecnología de los Computadores, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| |
Collapse
|
2
|
Zhao Q, Gouget G, Guo J, Yang S, Zhao T, Straus DB, Qian C, Oh N, Wang H, Murray CB, Kagan CR. Enhanced Carrier Transport in Strongly Coupled, Epitaxially Fused CdSe Nanocrystal Solids. NANO LETTERS 2021; 21:3318-3324. [PMID: 33792310 DOI: 10.1021/acs.nanolett.1c00860] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Strongly coupled, epitaxially fused colloidal nanocrystal (NC) solids are promising solution-processable semiconductors to realize optoelectronic devices with high carrier mobilities. Here, we demonstrate sequential, solid-state cation exchange reactions to transform epitaxially connected PbSe NC thin films into Cu2Se nanostructured thin-film intermediates and then successfully to achieve zinc-blende, CdSe NC solids with wide epitaxial necking along {100} facets. Transient photoconductivity measurements probe carrier transport at nanometer length scales and show a photoconductance of 0.28(1) cm2 V-1 s-1, the highest among CdSe NC solids reported. Atomic-layer deposition of a thin Al2O3 layer infiltrates and protects the structure from fusing into a polycrystalline thin film during annealing and further improves the photoconductance to 1.71(5) cm2 V-1 s-1 and the diffusion length to 760 nm. We fabricate field-effect transistors to study carrier transport at micron length scales and realize high electron mobilities of 35(3) cm2 V-1 s-1 with on-off ratios of 106 after doping.
Collapse
|
3
|
Gomez CM, Pan S, Braga HM, de Oliveira LS, Dalpian GM, Biesold-McGee GV, Lin Z, Santos SF, Souza JA. Possible Charge-Transfer-Induced Conductivity Enhancement in TiO 2 Microtubes Decorated with Perovskite CsPbBr 3 Nanocrystals. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:5408-5416. [PMID: 32337995 DOI: 10.1021/acs.langmuir.9b03871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Halide perovskite CsPbBr3 quantum dots (QDs) were synthesized via supersaturated recrystallization process and deposited on the surface of TiO2 microtubes forming local nano-heterostructures. Structural, morphological, and optical characterizations confirm the formation of heterostructures comprised of TiO2 microtube decorated with green-emitting CsPbBr3 nanocrystals. Optical characterizations reveal the presence of two band gap energies corresponding to CsPbBr3 (2.34 eV) and rutile-TiO2 (2.97 eV). Time-resolved photoluminescence decays indicate different charge dynamics when comparing both samples, revealing the interaction of CsPbBr3 QDs with the microtube surface and thus confirming the formation of local nano-heterostructures. The voltage-current measurements in the dark show an abrupt decrease in the electrical resistivity of the CsPbBr3/TiO2 heterostructure reaching almost 95% when compared with the pristine TiO2 microtube. This significant increase in the electrical conductivity is associated with charge transfer from perovskite nanocrystals into the semiconductor microtube, which can be used to fine tune its electronic properties. Besides controlling the electrical conductivity, decoration with semiconducting nanocrystals makes the hollow heterostructure photoluminescent, which can be classified as a multifunctionalization in a single device.
Collapse
Affiliation(s)
| | - Shuang Pan
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | | | | | | | - Gill Vincent Biesold-McGee
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Zhiqun Lin
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | | | | |
Collapse
|
4
|
Yuan P, Zhang R, Selenius E, Ruan P, Yao Y, Zhou Y, Malola S, Häkkinen H, Teo BK, Cao Y, Zheng N. Solvent-mediated assembly of atom-precise gold-silver nanoclusters to semiconducting one-dimensional materials. Nat Commun 2020; 11:2229. [PMID: 32376829 PMCID: PMC7203111 DOI: 10.1038/s41467-020-16062-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 04/09/2020] [Indexed: 01/10/2023] Open
Abstract
Bottom-up design of functional device components based on nanometer-sized building blocks relies on accurate control of their self-assembly behavior. Atom-precise metal nanoclusters are well-characterizable building blocks for designing tunable nanomaterials, but it has been challenging to achieve directed assembly to macroscopic functional cluster-based materials with highly anisotropic properties. Here, we discover a solvent-mediated assembly of 34-atom intermetallic gold-silver clusters protected by 20 1-ethynyladamantanes into 1D polymers with Ag-Au-Ag bonds between neighboring clusters as shown directly by the atomic structure from single-crystal X-ray diffraction analysis. Density functional theory calculations predict that the single crystals of cluster polymers have a band gap of about 1.3 eV. Field-effect transistors fabricated with single crystals of cluster polymers feature highly anisotropic p-type semiconductor properties with ≈1800-fold conductivity in the direction of the polymer as compared to cross directions, hole mobility of ≈0.02 cm2 V-1 s-1, and an ON/OFF ratio up to ≈4000. This performance holds promise for further design of functional cluster-based materials with highly anisotropic semiconducting properties.
Collapse
Affiliation(s)
- Peng Yuan
- State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China
| | - Ruihua Zhang
- State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China
| | - Elli Selenius
- Departments of Physics and Chemistry, Nanoscience Center, University of Jyväskylä, FI-40014, Jyväskylä, Finland
| | - Pengpeng Ruan
- State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China
| | - Yangrong Yao
- State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China
| | - Yang Zhou
- State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China
| | - Sami Malola
- Departments of Physics and Chemistry, Nanoscience Center, University of Jyväskylä, FI-40014, Jyväskylä, Finland
| | - Hannu Häkkinen
- Departments of Physics and Chemistry, Nanoscience Center, University of Jyväskylä, FI-40014, Jyväskylä, Finland.
| | - Boon K Teo
- State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China
| | - Yang Cao
- State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China.
| | - Nanfeng Zheng
- State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China.
| |
Collapse
|
5
|
Kar M, Rajbanshi B, Sarkar R, Pal S, Sarkar P. Periodically-ordered one and two dimensional CdTe QD superstructures: a path forward in photovoltaics. Phys Chem Chem Phys 2019; 21:19391-19402. [DOI: 10.1039/c9cp03529j] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
By using the state-of-the-art theoretical method, we herein explore the potentiality of covalently linked periodically-ordered 1D chain, 2D hexagonal and square ordered superstructures of CdTe QDs in photovoltaics.
Collapse
Affiliation(s)
- Moumita Kar
- Department of Chemistry
- Visva-Bharati University
- Santiniketan-731235
- India
| | - Biplab Rajbanshi
- Department of Chemistry
- Visva-Bharati University
- Santiniketan-731235
- India
| | - Ritabrata Sarkar
- Department of Chemistry
- University of Gour Banga
- Malda-732103
- India
| | - Sougata Pal
- Department of Chemistry
- University of Gour Banga
- Malda-732103
- India
| | - Pranab Sarkar
- Department of Chemistry
- Visva-Bharati University
- Santiniketan-731235
- India
| |
Collapse
|
6
|
Crisp RW, Kirkwood N, Grimaldi G, Kinge S, Siebbeles LDA, Houtepen AJ. Highly Photoconductive InP Quantum Dots Films and Solar Cells. ACS APPLIED ENERGY MATERIALS 2018; 1:6569-6576. [PMID: 30506040 PMCID: PMC6259048 DOI: 10.1021/acsaem.8b01453] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 10/23/2018] [Indexed: 05/05/2023]
Abstract
InP and InZnP colloidal quantum dots (QDs) are promising materials for application in light-emitting devices, transistors, photovoltaics, and photocatalytic cells. In addition to possessing an appropriate bandgap, high absorption coefficient, and high bulk carrier mobilities, the intrinsic toxicity of InP and InZnP is much lower than for competing QDs that contain Cd or Pb-providing a potentially safer commercial product. However, compared to other colloidal QDs, InP QDs remain sparsely used in devices and their electronic transport properties are largely unexplored. Here, we use time-resolved microwave conductivity measurements to study charge transport in films of InP and InZnP colloidal quantum dots capped with a variety of short ligands. We find that transport in InP QDs is dominated by trapping effects, which are mitigated in InZnP QDs. We improve charge carrier mobilities with a range of ligand-exchange treatments and for the best treatments reach mobilities and lifetimes on par with those of PbS QD films used in efficient solar cells. To demonstrate the device-grade quality of these films, we construct solar cells based on InP & InZnP QDs with power conversion efficiencies of 0.65 and 1.2%, respectively. This represents a large step forward in developing Cd- and Pb-free next-generation optoelectronic devices.
Collapse
Affiliation(s)
- Ryan W. Crisp
- Chemical
Engineering Department, Delft University
of Technology, Van der Maasweg 9, Delft2629 HZ , The Netherlands
| | - Nicholas Kirkwood
- Chemical
Engineering Department, Delft University
of Technology, Van der Maasweg 9, Delft2629 HZ , The Netherlands
| | - Gianluca Grimaldi
- Chemical
Engineering Department, Delft University
of Technology, Van der Maasweg 9, Delft2629 HZ , The Netherlands
| | - Sachin Kinge
- Toyota
Motor Europe, Materials Research & Development, Hoge Wei 33, Zaventem B-1930, Belgium
| | - Laurens D. A. Siebbeles
- Chemical
Engineering Department, Delft University
of Technology, Van der Maasweg 9, Delft2629 HZ , The Netherlands
| | - Arjan J. Houtepen
- Chemical
Engineering Department, Delft University
of Technology, Van der Maasweg 9, Delft2629 HZ , The Netherlands
- . Website: www.tudelft.nl/cheme/houtepengroup
| |
Collapse
|
7
|
Ahmadpour A, Asl AH, Fallah N. Synthesis and photocatalytic studies of TiO2-clinoptilolite on spent caustic wastewater treatment. PARTICULATE SCIENCE AND TECHNOLOGY 2017. [DOI: 10.1080/02726351.2017.1302534] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Amin Ahmadpour
- Faculty of Chemical, Gas and Petroleum Engineering, Semnan University, Semnan, Iran
| | - Ali Haghighi Asl
- Faculty of Chemical, Gas and Petroleum Engineering, Semnan University, Semnan, Iran
| | - Narges Fallah
- Chemical Engineering Department, Amirkabir University of Technology, Tehran, Iran
| |
Collapse
|
8
|
Zhu L, Richardson BJ, Yu Q. Inverted hybrid CdSe-polymer solar cells adopting PEDOT:PSS/MoO3 as dual hole transport layers. Phys Chem Chem Phys 2016; 18:3463-71. [PMID: 26750773 DOI: 10.1039/c5cp06677h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UNLABELLED Inverted CdSe quantum dots (QDs):poly (3-hexylthiophene) (P3HT) organic/inorganic hybrid solar cells (OIHSCs) with the PEDOT PSS/MoO3 dual hole transport layers (HTLs) showed superior performance over those with a single HTL of PEDOT PSS or MoO3. The enhanced electron blocking at the active layer/anode interface as well as the prevention of leakage current accounted for the enhancement in the efficiency of the solar cells with the dual HTLs. By adopting the inverted structure and using the dual HTLs, the resistive losses of the CdSe QDs:P3HT hybrid system at high illumination power were effectively prevented. Further study showed the structure of dual HTLs was applicable to the solar cells with CdSe QDs and nanorods (NRs) blended with poly(thienothiophene-co-benzodithiophenes)7-F20 (PTB7-F20).
Collapse
Affiliation(s)
- Leize Zhu
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA.
| | | | | |
Collapse
|
9
|
Sandeep CSS, Azpiroz JM, Evers WH, Boehme SC, Moreels I, Kinge S, Siebbeles LDA, Infante I, Houtepen AJ. Epitaxially connected PbSe quantum-dot films: controlled neck formation and optoelectronic properties. ACS NANO 2014; 8:11499-511. [PMID: 25347299 DOI: 10.1021/nn504679k] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Ligand exchange is a much-used method to increase the conductivity of colloidal quantum-dot films by replacing long insulating ligands on quantum-dot surfaces with shorter ones. Here we show that while some ligands indeed replace the original ones as expected, others may be used to controllably remove the native ligands and induce epitaxial necking of specific crystal facets. In particular, we demonstrate that amines strip lead oleate from the (100) surfaces of PbSe quantum dots. This leads to necking of QDs and results in cubic superlattices of epitaxially connected QDs. The number of amine head-groups as well as the carbon chain length of linear diamines is shown to control the extent of necking. DFT calculations show that removal of Pb(oleate)2 from (100) surfaces is exothermic for all amines, but the driving force increases as monoamines < long diamines < short diamines < tetramines. The neck formation and cubic ordering results in a higher optical absorption cross section and higher charge carrier mobilities, thereby showing that the use of the proper multidentate amine molecules is a powerful tool to create supercrystals of epitaxially connected PbSe QDs with controlled electronic coupling.
Collapse
Affiliation(s)
- C S Suchand Sandeep
- Optoelectronic Material Section, Department of Chemical Engineering, Delft University of Technology , Julianalaan 136, 2628 BL Delft, The Netherlands
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Jung J, Yoon YJ, He M, Lin Z. Organic-inorganic nanocomposites composed of conjugated polymers and semiconductor nanocrystals for photovoltaics. ACTA ACUST UNITED AC 2014. [DOI: 10.1002/polb.23612] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Jaehan Jung
- School of Materials Science and Engineering; Georgia Institute of Technology; Atlanta Georgia 30332
| | - Young Jun Yoon
- School of Materials Science and Engineering; Georgia Institute of Technology; Atlanta Georgia 30332
| | - Ming He
- School of Materials Science and Engineering; Georgia Institute of Technology; Atlanta Georgia 30332
| | - Zhiqun Lin
- School of Materials Science and Engineering; Georgia Institute of Technology; Atlanta Georgia 30332
| |
Collapse
|
11
|
Delerue C. From semiconductor nanocrystals to artificial solids with dimensionality below two. Phys Chem Chem Phys 2014; 16:25734-40. [PMID: 25045765 DOI: 10.1039/c4cp01878h] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two-dimensional films of semiconductors can be patterned into super-lattices with nanoscale periodicity, using top-down (lithography) or bottom-up approaches. In particular, square and honeycomb lattices of semiconductor nanocrystals have been recently synthesized using oriented attachment. We have performed atomistic tight-binding calculations of the conduction bands of super-lattices of CdSe. We consider spherical nanocrystals connected by horizontal cylinders and we investigate the band structure between two extreme limits, the uniform two-dimensional film, and the assembly of disconnected nanocrystals. Using this model system, we explain how rich band structures emerge from the periodic nano-geometry, including Dirac cones and non-trivial flat bands in honeycomb lattices. The possibility to build non-conventional band structures using multi-orbital artificial atoms (nanocrystals) opens up new prospects.
Collapse
|
12
|
Disorder strongly enhances Auger recombination in conductive quantum-dot solids. Nat Commun 2014; 4:2329. [PMID: 24029819 PMCID: PMC3778520 DOI: 10.1038/ncomms3329] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 07/18/2013] [Indexed: 12/05/2022] Open
Abstract
Auger recombination (AR) can be an important loss mechanism for optoelectronic devices, but it is typically not very efficient at low excitation densities. Here we show that in conductive quantum-dot solids, AR is the dominant charge carrier decay path even at excitation densities as low as 10−3 per quantum dot, and that AR becomes faster as the charge carrier mobility increases. Monte Carlo simulations reveal that this efficient AR results from charge carrier congregation in ‘Auger hot spots’: lower-energy sites that are present because of energy disorder. Disorder-enhanced AR is a general effect that is expected to be active in all disordered materials. The observed efficient AR is an issue of concern for devices that work at charge carrier densities in excess of ~10−3 charge carriers per quantum dot. At the same time, efficient carrier congregation could be exploited for fast optical switching or to achieve optical gain in the near infrared. Understanding Auger recombination is important for building better optoelectronics, as it is a crucial loss mechanism. Gao et al. study it in conductive quantum dot solids, and find that it is the dominant charge carrier decay path, even for very low excitation densities.
Collapse
|
13
|
Sandeep CSS, ten Cate S, Schins JM, Savenije TJ, Liu Y, Law M, Kinge S, Houtepen AJ, Siebbeles LDA. High charge-carrier mobility enables exploitation of carrier multiplication in quantum-dot films. Nat Commun 2014; 4:2360. [PMID: 23974282 PMCID: PMC3759061 DOI: 10.1038/ncomms3360] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 07/26/2013] [Indexed: 11/24/2022] Open
Abstract
Carrier multiplication, the generation of multiple electron–hole pairs by a single photon, is of great interest for solar cells as it may enhance their photocurrent. This process has been shown to occur efficiently in colloidal quantum dots, however, harvesting of the generated multiple charges has proved difficult. Here we show that by tuning the charge-carrier mobility in quantum-dot films, carrier multiplication can be optimized and may show an efficiency as high as in colloidal dispersion. Our results are explained quantitatively by the competition between dissociation of multiple electron–hole pairs and Auger recombination. Above a mobility of ~1 cm2 V−1 s−1, all charges escape Auger recombination and are quantitatively converted to free charges, offering the prospect of cheap quantum-dot solar cells with efficiencies in excess of the Shockley–Queisser limit. In addition, we show that the threshold energy for carrier multiplication is reduced to twice the band gap of the quantum dots. Carrier multiplication effects are of promise for enhancement of solar cells, but have been difficult to exploit in such devices. Here, the authors demonstrate how carrier multiplication in quantum-dot films can be considerably enhanced by appropriate tuning of the charge-carrier mobility.
Collapse
Affiliation(s)
- C S Suchand Sandeep
- Optoelectronic Materials section, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628BL Delft, The Netherlands
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Ogarev VA, Rudoi VM, Dement’eva OV. Prospects for increasing the efficiency of water photodecomposition on inorganic semiconductors. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2014. [DOI: 10.1134/s0036024414020174] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
15
|
Mahadevu R, Yelameli AR, Panigrahy B, Pandey A. Controlling light absorption in charge-separating core/shell semiconductor nanocrystals. ACS NANO 2013; 7:11055-11063. [PMID: 24251926 DOI: 10.1021/nn404749n] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Semiconductor nanocrystals of different formulations have been extensively studied for use in thin-film photovoltaics. Materials used in such devices need to satisfy the stringent requirement of having large absorption cross sections. Hence, type-II semiconductor nanocrystals that are generally considered to be poor light absorbers have largely been ignored. In this article, we show that type-II semiconductor nanocrystals can be tailored to match the light-absorption abilities of other types of nanostructures as well as bulk semiconductors. We synthesize type-II ZnTe/CdS core/shell nanocrystals. This material is found to exhibit a tunable band gap as well as absorption cross sections that are comparable to CdTe. This result has significant implications for thin-film photovoltaics, where the use of type-II nanocrystals instead of pure semiconductors can improve charge separation while also providing a much needed handle to regulate device composition.
Collapse
Affiliation(s)
- Rekha Mahadevu
- Solid State and Structural Chemistry Unit, Indian Institute of Science , Bangalore 560012, India
| | | | | | | |
Collapse
|
16
|
Kramer IJ, Sargent EH. The Architecture of Colloidal Quantum Dot Solar Cells: Materials to Devices. Chem Rev 2013; 114:863-82. [DOI: 10.1021/cr400299t] [Citation(s) in RCA: 401] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Illan J. Kramer
- Edward S. Rogers Department of Electrical & Computer Engineering, University of Toronto, 10 King’s College Road, Toronto, Ontario M5S 3G4, Canada
| | - Edward H. Sargent
- Edward S. Rogers Department of Electrical & Computer Engineering, University of Toronto, 10 King’s College Road, Toronto, Ontario M5S 3G4, Canada
| |
Collapse
|
17
|
Yang Y, Liu Z, Lian T. Bulk transport and interfacial transfer dynamics of photogenerated carriers in CdSe quantum dot solid electrodes. NANO LETTERS 2013; 13:3678-3683. [PMID: 23855506 DOI: 10.1021/nl401573x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Practical solar-to-fuel conversion applications of quantum-confined semiconductor crystals require their integration into electrodes. We show that photogenerated electrons in quantum dot solid electrodes can be transported to the aqueous interface to reduce methyl viologen with 100% quantum efficiency and an effective time constant of 12 ± 2 ps. The charge separated state had a half-life of 200 ± 10 ns, limited by hole transport within the solid.
Collapse
Affiliation(s)
- Ye Yang
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | | | | |
Collapse
|
18
|
YU X, WANG Y, MENG X, YANG J. Preparation and characterization of Pd/N codoped TiO2 photocatalysts with high visible light photocatalytic activity. CHINESE JOURNAL OF CATALYSIS 2013. [DOI: 10.1016/s1872-2067(12)60597-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
19
|
Deng S, Ju H. Electrogenerated chemiluminescence of nanomaterials for bioanalysis. Analyst 2013; 138:43-61. [DOI: 10.1039/c2an36122a] [Citation(s) in RCA: 172] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
20
|
Gao Y, Aerts M, Sandeep CSS, Talgorn E, Savenije TJ, Kinge S, Siebbeles LDA, Houtepen AJ. Photoconductivity of PbSe quantum-dot solids: dependence on ligand anchor group and length. ACS NANO 2012; 6:9606-14. [PMID: 23078408 DOI: 10.1021/nn3029716] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The assembly of quantum dots is an essential step toward many of their potential applications. To form conductive solids from colloidal quantum dots, ligand exchange is required. Here we study the influence of ligand replacement on the photoconductivity of PbSe quantum-dot solids, using the time-resolved microwave conductivity technique. Bifunctional replacing ligands with amine, thiol, or carboxylic acid anchor groups of various lengths are used to assemble quantum solids via a layer-by-layer dip-coating method. We find that when the ligand lengths are the same, the charge carrier mobility is higher in quantum-dot solids with amine ligands, while in quantum-dot solids with thiol ligands the charge carrier lifetime is longer. If the anchor group is the same, the charge carrier mobility is ligand length dependent. The results show that the diffusion length of charge carriers can reach several hundred nanometers.
Collapse
Affiliation(s)
- Yunan Gao
- Optoelectronic Material Section, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628 BL, Delft, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Shibu ES, Sonoda A, Tao Z, Feng Q, Furube A, Masuo S, Wang L, Tamai N, Ishikawa M, Biju V. Photofabrication of fullerene-shelled quantum dots supramolecular nanoparticles for solar energy harvesting. ACS NANO 2012; 6:1601-1608. [PMID: 22260241 DOI: 10.1021/nn204567d] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Quantum dots-based electron donor-acceptor systems play a rising role in the design of renewable and carbon-free energy harvesting technologies. In this article, we discuss the photofabrication of fullerene-shelled quantum dots supramolecular nanoparticles, in which the fullerene shell acts as not only a well-defined electron acceptor but also a robust protecting layer against the photocorrosion of the quantum dot core. We evaluate the ensemble and single-molecule electron transfer from the core to the shell in the nanoparticles and the photocurrent response of a photoelectrochemical cell constructed using the nanoparticles. The supramolecular nanoparticle has been prepared by the covalent tethering of a fullerene-thiol monolayer to the quantum dot followed by the photochemical reactions of free fullerene-thiol to the tethered monolayer. The nanoparticles are characterized using scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. Correlated single-photon emission and the two-state ON-OFF photoluminescence show that single quantum dots are included in the supramolecular nanoparticles. The fullerene-shells suppress the blinking of single quantum dots by acting as well-defined electron traps, without allowing the transfer of Auger electrons to unknown traps. Electron transfer from the quantum dot-core to the fullerene-shell is apparent from the short ON and OFF durations in the photoluminescence intensity trajectories of single quantum dots, quenching of the photoluminescence intensity and lifetime of quantum dots at the ensemble level, and the characteristic transient absorption band of the anion radical of fullerene. We next construct a photoelectrochemical cell using the supramolecular nanoparticles, and the transferred electron is externally driven in the cell to generate ∼400 μA/cm(2) photocurrent. Electron transfer from the highly stable quantum dots to the protecting fullerene-shells places the supramolecular nanoparticles among the most promising antenna systems for the construction of cost-effective and stable next generation solar energy harvesting systems.
Collapse
Affiliation(s)
- Edakkattuparambil Sidharth Shibu
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Gao Y, Talgorn E, Aerts M, Trinh MT, Schins JM, Houtepen AJ, Siebbeles LDA. Enhanced hot-carrier cooling and ultrafast spectral diffusion in strongly coupled PbSe quantum-dot solids. NANO LETTERS 2011; 11:5471-6. [PMID: 22039918 DOI: 10.1021/nl203235u] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
PbSe quantum-dot solids are of great interest for low cost and efficient photodetectors and solar cells. We have prepared PbSe quantum-dot solids with high charge carrier mobilities using layer-by-layer dip-coating with 1,2-ethanediamine as substitute capping ligands. Here we present a time and energy resolved transient absorption spectroscopy study on the kinetics of photogenerated charge carriers, focusing on 0-5 ps after photoexcitation. We compare the observed carrier kinetics to those for quantum dots in dispersion and show that the intraband carrier cooling is significantly faster in quantum-dot solids. In addition we find that carriers diffuse from higher to lower energy sites in the quantum-dot solid within several picoseconds.
Collapse
Affiliation(s)
- Yunan Gao
- Optoelectronic Material Section, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628 BL, Delft, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
23
|
Talgorn E, Gao Y, Aerts M, Kunneman LT, Schins JM, Savenije TJ, van Huis MA, van der Zant HSJ, Houtepen AJ, Siebbeles LDA. Unity quantum yield of photogenerated charges and band-like transport in quantum-dot solids. NATURE NANOTECHNOLOGY 2011; 6:733-9. [PMID: 21946709 DOI: 10.1038/nnano.2011.159] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 08/18/2011] [Indexed: 05/07/2023]
Abstract
Solid films of colloidal quantum dots show promise in the manufacture of photodetectors and solar cells. These devices require high yields of photogenerated charges and high carrier mobilities, which are difficult to achieve in quantum-dot films owing to a strong electron-hole interaction and quantum confinement. Here, we show that the quantum yield of photogenerated charges in strongly coupled PbSe quantum-dot films is unity over a large temperature range. At high photoexcitation density, a transition takes place from hopping between localized states to band-like transport. These strongly coupled quantum-dot films have electrical properties that approach those of crystalline bulk semiconductors, while retaining the size tunability and cheap processing properties of colloidal quantum dots.
Collapse
Affiliation(s)
- Elise Talgorn
- Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
| | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Zhang Y, Miszta K, Kudera S, Manna L, Di Fabrizio E, Krahne R. Spatially resolved photoconductivity of thin films formed by colloidal octapod-shaped CdSe/CdS nanocrystals. NANOSCALE 2011; 3:2964-2970. [PMID: 21643586 DOI: 10.1039/c1nr10251f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We studied the optical absorption and photoconductive properties of thin films consisting of core-shell octapod-shaped nanocrystals, which consisted of CdS pods that branch out from a CdSe core. The current-voltage characteristics were measured at room and cryogenic temperatures and agreed well with a phenomenological exponential fitting model, from which we could extract the sheet resistance and the average voltage barrier for the charge tunneling between the octapods. The temperature dependence of the photocurrent showed temperature activated behavior above 220 K and a non-Arrhenius exponential (T/T(0))(n) dispersion below 220 K. Furthermore, we mapped the photocurrent generation within the octapod film via scanning photocurrent microscopy, which revealed photocurrent enhancement near micron-size voids and spatial shifts of the photocurrent maxima with bias voltage.
Collapse
Affiliation(s)
- Yang Zhang
- Italian Institute of Technology, Via Morego 30, 16163 Genoa, Italy
| | | | | | | | | | | |
Collapse
|
25
|
Talgorn E, de Vries MA, Siebbeles LDA, Houtepen AJ. Photoconductivity enhancement in multilayers of CdSe and CdTe quantum dots. ACS NANO 2011; 5:3552-8. [PMID: 21517097 DOI: 10.1021/nn2009134] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Charge separation at the interface between CdSe and CdTe quantum dots was investigated by comparing the photoconductivity of films consisting of only CdSe or CdTe quantum dots to that of films with alternating layers of CdSe and CdTe quantum dots. The photoconductivity for alternating layers is three times higher than for the single component layers. Different possible mechanisms are discussed, and it is concluded that the dissociation of photoexcited excitons into spatially separated mobile charge carriers at the CdSe/CdTe QD interfaces is the most likely explanation. Given that the yield of charge carrier photogeneration in the multilayer sample is at most one, and under the assumption that the mobility of QD layers in unchanged, we conclude that the yield of charge carrier photogeneration in the single component samples is at most one-third. The thickness of the individual CdSe and CdTe layers was varied, resulting in different distances between the CdSe/CdTe interfaces. The photoconductivity increased with respect to films of only CdSe or CdTe when these interfaces were separated by only one or two quantum dot layers, which implies that exciton diffusion is inefficient.
Collapse
Affiliation(s)
- Elise Talgorn
- Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
| | | | | | | |
Collapse
|
26
|
Lee JS, Kovalenko MV, Huang J, Chung DS, Talapin DV. Band-like transport, high electron mobility and high photoconductivity in all-inorganic nanocrystal arrays. NATURE NANOTECHNOLOGY 2011; 6:348-52. [PMID: 21516091 DOI: 10.1038/nnano.2011.46] [Citation(s) in RCA: 381] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Accepted: 03/08/2011] [Indexed: 05/20/2023]
Abstract
Flexible, thin-film electronic and optoelectronic devices typically involve a trade-off between performance and fabrication cost. For example, solution-based deposition allows semiconductors to be patterned onto large-area substrates to make solar cells and displays, but the electron mobility in solution-deposited semiconductor layers is much lower than in semiconductors grown at high temperatures from the gas phase. Here, we report band-like electron transport in arrays of colloidal cadmium selenide nanocrystals capped with the molecular metal chalcogenide complex In(2)Se(4)(2-), and measure electron mobilities as high as 16 cm(2) V(-1) s(-1), which is about an order of magnitude higher than in the best solution-processed organic and nanocrystal devices so far. We also use CdSe/CdS core-shell nanoparticles with In(2)Se(4)(2-) ligands to build photodetectors with normalized detectivity D* > 1 × 10(13) Jones (I Jones = 1 cm Hz(1/2) W(-1)), which is a record for II-VI nanocrystals. Our approach does not require high processing temperatures, and can be extended to different nanocrystals and inorganic surface ligands.
Collapse
Affiliation(s)
- Jong-Soo Lee
- Department of Chemistry and James Frank Institute, University of Chicago, Chicago, Illinois 60637, USA
| | | | | | | | | |
Collapse
|
27
|
Chen J, Lei W, Deng WQ. Reduced charge recombination in a co-sensitized quantum dot solar cell with two different sizes of CdSe quantum dot. NANOSCALE 2011; 3:674-677. [PMID: 21132215 DOI: 10.1039/c0nr00591f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
An efficient photoelectrode is fabricated by sequentially assembling 2.5 nm and 3.5 nm CdSe quantum dots (QDs) onto a TiO2 film. As revealed by UV-vis absorption spectroscopy, two sizes of CdSe QD can be effectively adsorbed on the TiO2 film. With a broader light absorption range and better coverage of CdSe QDs on the TiO2 film, a power conversion efficiency of 1.26% has been achieved for the TiO2/CdSe QD (2.5 nm)/CdSe QD (3.5 nm) cell under the illumination of one Sun (AM 1.5G, 100 mW cm(-2)). Electrochemical impedance spectroscopy shows that the electron lifetime for the device based on TiO2/CdSe QD (2.5 nm)/CdSe QD (3.5 nm) is longer than that for devices based on TiO2/CdSe QD (2.5 nm) and TiO2/CdSe QD (3.5 nm), indicating that the charge recombination at the interface is reduced by sensitizing with two kinds of CdSe QDs.
Collapse
Affiliation(s)
- J Chen
- School of Electronic Science and Engineering, Southeast University, Nanjing, 210096, China
| | | | | |
Collapse
|
28
|
Ling T, Wu MK, Niu KY, Yang J, Gao ZM, Sun J, Du XW. Spongy structure of CdS nanocrystals decorated with dye molecules for semiconductor sensitized solar cells. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c0jm03530k] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
29
|
Kamat PV, Tvrdy K, Baker DR, Radich EJ. Beyond Photovoltaics: Semiconductor Nanoarchitectures for Liquid-Junction Solar Cells. Chem Rev 2010; 110:6664-88. [DOI: 10.1021/cr100243p] [Citation(s) in RCA: 676] [Impact Index Per Article: 48.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Prashant V. Kamat
- Radiation Laboratory and Departments of Chemistry & Biochemistry and Chemical & Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Kevin Tvrdy
- Radiation Laboratory and Departments of Chemistry & Biochemistry and Chemical & Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - David R. Baker
- Radiation Laboratory and Departments of Chemistry & Biochemistry and Chemical & Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Emmy J. Radich
- Radiation Laboratory and Departments of Chemistry & Biochemistry and Chemical & Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| |
Collapse
|