1
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Du Y, Arifuddin AA, Qin H, Yan S, Zou Z. Thermal-Stabilized Protonated TiO 2 for Heat-Accelerated Photoelectrochemical Water Splitting. J Phys Chem Lett 2024; 15:5681-5688. [PMID: 38767856 DOI: 10.1021/acs.jpclett.4c01154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Enhancing the charge separation efficiency is a big challenge that limits the energy conversion efficiency of photoelectrochemical (PEC) water splitting. Surface states generated by protonation of TiO2 are the efficient charge separation passageways to massively accept or transfer the photogenerated electrons. However, a challenge is to avoid the deprotonation of a protonated TiO2 photoelectrode at the operation temperature. Here, we found that the terminal hydroxyl group (OHT) as surface states on the TiO2 surface generated via electrochemical protonation of TiO2 at 90 °C [90-TiO2-x-(OH)x] is thermally stable. As a result, the thermally enhanced photocurrent of the 90-TiO2-x-(OH)x electrode reached 1.05 mA cm-2 under 80 °C, and the stability was maintained up to 10 h with a slight photocurrent decrease of 3%. The thermally stable surface states as charge separation paths provide an effective method to couple the heat field with the PEC process via thermal-stimulating hopping of polarons.
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Affiliation(s)
- Yu Du
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, 22 Hankou Road, Nanjing, Jiangsu 210093, People's Republic of China
| | - Alam Andi Arifuddin
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, 22 Hankou Road, Nanjing, Jiangsu 210093, People's Republic of China
| | - Hao Qin
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, 22 Hankou Road, Nanjing, Jiangsu 210093, People's Republic of China
- Wuxi Little Swan Electric Company, Limited, 18 Changjiang South Road, Wuxi, Jiangsu 214028, People's Republic of China
| | - Shicheng Yan
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, 22 Hankou Road, Nanjing, Jiangsu 210093, People's Republic of China
| | - Zhigang Zou
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, 22 Hankou Road, Nanjing, Jiangsu 210093, People's Republic of China
- Jiangsu Key Laboratory for Nano Technology, Nanjing University, 22 Hankou Road, Nanjing, Jiangsu 210093, People's Republic of China
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2
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Du Y, Yan S, Zou Z. Thermally Accelerated Surface Polaron Hopping in Photoelectrochemical Water Splitting. J Phys Chem Lett 2023; 14:413-419. [PMID: 36622299 DOI: 10.1021/acs.jpclett.2c03567] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Electron-hole separation is a main challenge that limits the energy efficiency of photoelectrochemical water splitting for hydrogen fuel production. Surface polaron states with an energy level distribution near the conduction band are highly efficient charge separation passageways to massively accept or transfer the photogenerated electrons. Here, we found that the charge separation via surface polaron states could be further enhanced by heating (<100 °C) to accelerate the electron mobility of surface polaron states. As a result of heating from 30 to 70 °C, the saturated photocurrent increased about 34.5% under 1 sun and 18.3% under 10 suns from heat-induced increase in electron flux of surface polaron states. The heat-sensitive surface-state electron transfer provides a new heat-photoelectricity coupling mechanism to guide the design of new photoanodes that are available for complementary multienergy systems with high energy efficiency.
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Affiliation(s)
- Yu Du
- Collaborative Innovation Center of Advanced Microstructures, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, Nanjing University, No. 22 Hankou Road, Nanjing, Jiangsu 210093, P. R. China
| | - Shicheng Yan
- Collaborative Innovation Center of Advanced Microstructures, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, Nanjing University, No. 22 Hankou Road, Nanjing, Jiangsu 210093, P. R. China
| | - Zhigang Zou
- Collaborative Innovation Center of Advanced Microstructures, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, Nanjing University, No. 22 Hankou Road, Nanjing, Jiangsu 210093, P. R. China
- National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory for Nano Technology, School of Physics, Nanjing University, No. 22 Hankou Road, Nanjing, Jiangsu 210093, P. R. China
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3
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Mitrić P, Janković V, Vukmirović N, Tanasković D. Spectral Functions of the Holstein Polaron: Exact and Approximate Solutions. PHYSICAL REVIEW LETTERS 2022; 129:096401. [PMID: 36083668 DOI: 10.1103/physrevlett.129.096401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 05/02/2022] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
It is generally accepted that the dynamical mean field theory gives a good solution of the Holstein model, but only in dimensions greater than two. Here, we show that this theory, which becomes exact in the weak coupling and in the atomic limit, provides an excellent, numerically cheap, approximate solution for the spectral function of the Holstein model in the whole range of parameters, even in one dimension. To establish this, we make a detailed comparison with the spectral functions that we obtain using the newly developed momentum-space numerically exact hierarchical equations of motion method, which yields electronic correlation functions directly in real time. We crosscheck these conclusions with our path integral quantum Monte Carlo and exact diagonalization results, as well as with the available numerically exact results from the literature.
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Affiliation(s)
- Petar Mitrić
- Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
| | - Veljko Janković
- Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
| | - Nenad Vukmirović
- Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
| | - Darko Tanasković
- Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
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4
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Hsu CP. Reorganization energies and spectral densities for electron transfer problems in charge transport materials. Phys Chem Chem Phys 2020; 22:21630-21641. [DOI: 10.1039/d0cp02994g] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Various contributions to the outer reorganization energy of an electron transfer system and their theoretical and computational aspects have been discussed.
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Affiliation(s)
- Chao-Ping Hsu
- 128 Academia Road Section 2
- Institute of Chemistry
- Academia Sinica
- Taipei
- Taiwan
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5
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Nakayama Y, Mizuno Y, Hikasa M, Yamamoto M, Matsunami M, Ideta S, Tanaka K, Ishii H, Ueno N. Single-Crystal Pentacene Valence-Band Dispersion and Its Temperature Dependence. J Phys Chem Lett 2017; 8:1259-1264. [PMID: 28240895 DOI: 10.1021/acs.jpclett.7b00082] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The electronic structures of the highest occupied molecular orbital (HOMO) or the HOMO-derived valence bands dominate the transport nature of positive charge carriers (holes) in organic semiconductors. In the present study, the valence-band structures of single-crystal pentacene and the temperature dependence of their energy-momentum dispersion relations are successfully demonstrated using angle-resolved ultraviolet photoelectron spectroscopy (ARUPS). For the shallowest valence band, the intermolecular transfer integral and effective mass of the holes are evaluated as 43.1 meV and 3.43 times the electron rest mass, respectively, at room temperature along the crystallographic direction for which the widest energy dispersion is expected. The temperature dependence of the ARUPS results reveals that the transfer integral values (hole effective mass) are enhanced (reduced) by ∼20% on cooling the sample to 110 K.
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Affiliation(s)
- Yasuo Nakayama
- Department of Pure and Applied Chemistry, Graduate School of Science and Technology, Tokyo University of Science , 2641 Yamazaki, Noda 278-8510, Japan
| | - Yuta Mizuno
- Graduate School of Advanced Integration Science, Chiba University , 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Masataka Hikasa
- Department of Pure and Applied Chemistry, Graduate School of Science and Technology, Tokyo University of Science , 2641 Yamazaki, Noda 278-8510, Japan
| | - Masayuki Yamamoto
- Graduate School of Advanced Integration Science, Chiba University , 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Masaharu Matsunami
- UVSOR Facility, Institute for Molecular Science (IMS), National Institutes of Natural Sciences , 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
| | - Shinichiro Ideta
- UVSOR Facility, Institute for Molecular Science (IMS), National Institutes of Natural Sciences , 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
| | - Kiyohisa Tanaka
- UVSOR Facility, Institute for Molecular Science (IMS), National Institutes of Natural Sciences , 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
| | - Hisao Ishii
- Graduate School of Advanced Integration Science, Chiba University , 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
- Center for Frontier Science, Chiba University , 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Nobuo Ueno
- Graduate School of Advanced Integration Science, Chiba University , 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
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6
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Di Sante D, Fratini S, Dobrosavljević V, Ciuchi S. Disorder-Driven Metal-Insulator Transitions in Deformable Lattices. PHYSICAL REVIEW LETTERS 2017; 118:036602. [PMID: 28157337 DOI: 10.1103/physrevlett.118.036602] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Indexed: 06/06/2023]
Abstract
We show that, in the presence of a deformable lattice potential, the nature of the disorder-driven metal-insulator transition is fundamentally changed with respect to the noninteracting (Anderson) scenario. For strong disorder, even a modest electron-phonon interaction is found to dramatically renormalize the random potential, opening a mobility gap at the Fermi energy. This process, which reflects disorder-enhanced polaron formation, is here given a microscopic basis by treating the lattice deformations and Anderson localization effects on the same footing. We identify an intermediate "bad insulator" transport regime which displays resistivity values exceeding the Mott-Ioffe-Regel limit and with a negative temperature coefficient, as often observed in strongly disordered metals. Our calculations reveal that this behavior originates from significant temperature-induced rearrangements of electronic states due to enhanced interaction effects close to the disorder-driven metal-insulator transition.
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Affiliation(s)
- Domenico Di Sante
- Institute of Physics and Astrophysics, University of Würzburg, Würzburg, Germany
- Consiglio Nazionale delle Ricerche (CNR-SPIN), Via Vetoio, L'Aquila, Italy
| | - Simone Fratini
- Institut Néel-CNRS and Université Grenoble Alpes, Boîte Postale 166, F-38042 Grenoble Cedex 9, France
| | - Vladimir Dobrosavljević
- Department of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
| | - Sergio Ciuchi
- Department of Physical and Chemical Sciences, University of L'Aquila, Via Vetoio, L'Aquila, Italy I-67100
- Consiglio Nazionale delle Ricerche (CNR-ISC) Via dei Taurini, Rome, Italy I-00185
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7
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Raghavan S, Zhang JY, Shoron OF, Stemmer S. Probing the Metal-Insulator Transition in BaTiO_{3} by Electrostatic Doping. PHYSICAL REVIEW LETTERS 2016; 117:037602. [PMID: 27472141 DOI: 10.1103/physrevlett.117.037602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Indexed: 06/06/2023]
Abstract
The metal-to-insulator transition in BaTiO_{3} is investigated using electrostatic doping, which avoids effects from disorder and strain that would accompany chemical doping. SmTiO_{3}/BaTiO_{3}/SrTiO_{3} heterostructures are doped with a constant sheet carrier density of 3×10^{14} cm^{-2} that is introduced via the polar SmTiO_{3}/BaTiO_{3} interface. Below a critical BaTiO_{3} thickness, the structures exhibit metallic behavior with high carrier mobilities at low temperatures, similar to SmTiO_{3}/SrTiO_{3} interfaces. Above this thickness, data indicate that the BaTiO_{3} layer becomes ferroelectric. The BaTiO_{3} lattice parameters increase to a value consistent with a strained, tetragonal unit cell, the structures are insulating below ∼125 K, and the mobility drops by more than an order of magnitude, indicating self-trapping of carriers. The results shed light on the interplay between charge carriers and ferroelectricity.
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Affiliation(s)
- Santosh Raghavan
- Materials Department, University of California, Santa Barbara, California 93106-5050, USA
| | - Jack Y Zhang
- Materials Department, University of California, Santa Barbara, California 93106-5050, USA
| | - Omor F Shoron
- Materials Department, University of California, Santa Barbara, California 93106-5050, USA
| | - Susanne Stemmer
- Materials Department, University of California, Santa Barbara, California 93106-5050, USA
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8
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Song L, Shi Q. Calculation of correlated initial state in the hierarchical equations of motion method using an imaginary time path integral approach. J Chem Phys 2015; 143:194106. [DOI: 10.1063/1.4935799] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Linze Song
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, China
| | - Qiang Shi
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, China
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9
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Ifland B, Peretzki P, Kressdorf B, Saring P, Kelling A, Seibt M, Jooss C. Current-voltage characteristics of manganite-titanite perovskite junctions. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2015; 6:1467-84. [PMID: 26199851 PMCID: PMC4505172 DOI: 10.3762/bjnano.6.152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 06/16/2015] [Indexed: 06/05/2023]
Abstract
After a general introduction into the Shockley theory of current voltage (J-V) characteristics of inorganic and organic semiconductor junctions of different bandwidth, we apply the Shockley theory-based, one diode model to a new type of perovskite junctions with polaronic charge carriers. In particular, we studied manganite-titanate p-n heterojunctions made of n-doped SrTi1- y Nb y O3, y = 0.002 and p-doped Pr1- x Ca x MnO3, x = 0.34 having a strongly correlated electron system. The diffusion length of the polaron carriers was analyzed by electron beam-induced current (EBIC) in a thin cross plane lamella of the junction. In the J-V characteristics, the polaronic nature of the charge carriers is exhibited mainly by the temperature dependence of the microscopic parameters, such as the hopping mobility of the series resistance and a colossal electro-resistance (CER) effect in the parallel resistance. We conclude that a modification of the Shockley equation incorporating voltage-dependent microscopic polaron parameters is required. Specifically, the voltage dependence of the reverse saturation current density is analyzed and interpreted as a voltage-dependent electron-polaron hole-polaron pair generation and separation at the interface.
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Affiliation(s)
- Benedikt Ifland
- Institute of Materials Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen, Germany
| | - Patrick Peretzki
- 4th Physical Institute, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen, Germany
| | - Birte Kressdorf
- Institute of Materials Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen, Germany
| | - Philipp Saring
- 4th Physical Institute, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen, Germany
| | - Andreas Kelling
- Institute of Materials Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen, Germany
| | - Michael Seibt
- 4th Physical Institute, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen, Germany
| | - Christian Jooss
- Institute of Materials Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen, Germany
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10
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Song L, Shi Q. A new approach to calculate charge carrier transport mobility in organic molecular crystals from imaginary time path integral simulations. J Chem Phys 2015; 142:174103. [DOI: 10.1063/1.4919061] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Linze Song
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, China
| | - Qiang Shi
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, China
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11
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Mishchenko AS, Nagaosa N, De Filippis G, de Candia A, Cataudella V. Mobility of Holstein polaron at finite temperature: an unbiased approach. PHYSICAL REVIEW LETTERS 2015; 114:146401. [PMID: 25910142 DOI: 10.1103/physrevlett.114.146401] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Indexed: 06/04/2023]
Abstract
We present the first unbiased results for the mobility μ of a one-dimensional Holstein polaron obtained by numerical analytic continuation combined with diagrammatic and worldline Monte Carlo methods in the thermodynamic limit. We have identified for the first time several distinct regimes in the λ-T plane including a band conduction region, incoherent metallic region, an activated hopping region, and a high-temperature saturation region. We observe that although mobilities and mean free paths at different values of λ differ by many orders of magnitude at small temperatures, their values at T larger than the bandwidth become very close to each other.
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Affiliation(s)
- A S Mishchenko
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- NRC "Kurchatov Institute", 123182 Moscow, Russia
| | - N Nagaosa
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan
| | - G De Filippis
- SPIN-CNR and Dipartimento di Fisica, Università di Napoli Federico II, I-80126 Napoli, Italy
| | - A de Candia
- SPIN-CNR and Dipartimento di Fisica, Università di Napoli Federico II, I-80126 Napoli, Italy
- INFN, Sezione di Napoli, Complesso Universitario di Monte S. Angelo, I-80126 Napoli, Italy
| | - V Cataudella
- SPIN-CNR and Dipartimento di Fisica, Università di Napoli Federico II, I-80126 Napoli, Italy
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12
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Wang L, Long R, Prezhdo OV. Time-Domain Ab Initio Modeling of Photoinduced Dynamics at Nanoscale Interfaces. Annu Rev Phys Chem 2015; 66:549-79. [DOI: 10.1146/annurev-physchem-040214-121359] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Linjun Wang
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482;
- Department of Chemistry, University of Rochester, Rochester, New York 14627
| | - Run Long
- School of Physics and Complex & Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4, Ireland
| | - Oleg V. Prezhdo
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482;
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13
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Draxl C, Nabok D, Hannewald K. Organic/inorganic hybrid materials: challenges for ab initio methodology. Acc Chem Res 2014; 47:3225-32. [PMID: 25171272 DOI: 10.1021/ar500096q] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
CONSPECTUS: Organic/inorganic hybrid structures are most exciting since one can expect new properties that are absent in either of their building blocks. They open new perspectives toward the design and tailoring of materials with desired features and functions. Prerequisite for real progress is, however, the in-depth understanding of what happens on the atomic and electronic scale. In this respect, hybrid materials pose a challenge for electronic-structure theory. Methods that proved useful for describing one side may not be applicable for the other one, and they are likely to fail for the interfaces. In this Account, we address the question to what extent we can quantitatively describe hybrid materials and where we even miss a qualitative description. We note that we are dealing with extended systems and thus adopt a solid-state approach. Therefore, density-functional theory (DFT) and many-body perturbation theory (MBPT), the GW approach for charged and the Bethe-Salpeter equation for neutral excitations, are our methods of choice. We give a brief summary of the used methodology, focusing on those aspects where problems can be expected when materials of different character meet at an interface. These issues are then taken up when discussing hybrid materials. We argue when and why, for example, standard DFT may fall short when it comes to the electronic structure of organic/metal interfaces or where the framework of MBPT can or must take over. Selected examples of organic/inorganic interfaces, structural properties, electronic bands, optical excitation spectra, and charge-transport properties as obtained from DFT and MBPT highlight which properties can be reliably computed for such materials. The crucial role of van der Waals forces is shown for sexiphenyl films, where the subtle interplay between intermolecular and molecule-substrate interactions is decisive for growth and morphologies. With a PTCDA monolayer on metal surfaces we discuss the performance of DFT in terms of interfacial electronic structure. We face the problem of a so far hidden variable, namely, electron-vibrational coupling, regarding level alignment at interfaces between organic and inorganic semiconductors. Poly(para-phenylene) adsorbed on graphene and encapsulated in carbon nanotubes represent case studies to demonstrate the impact of polarization effects and exciton delocalization in optoelectronic excitations, respectively. Polaron-induced band narrowing and its consequences for charge transport in organic crystals is exemplified for the HOMO bandwidth in naphthalene crystals. On the basis of these prototypical systems, we discuss what is missing to reach predictive power on a quantitative level for organic/inorganic hybrid materials and, thus, open a perspective toward the computational discovery of new materials for optoelectronic applications.
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Affiliation(s)
- Claudia Draxl
- Physics Department and IRIS Adlershof, Humboldt-Universität zu Berlin, Zum Großen
Windkanal 6, D-12489 Berlin, Germany
| | - Dmitrii Nabok
- Physics Department and IRIS Adlershof, Humboldt-Universität zu Berlin, Zum Großen
Windkanal 6, D-12489 Berlin, Germany
| | - Karsten Hannewald
- Physics Department and IRIS Adlershof, Humboldt-Universität zu Berlin, Zum Großen
Windkanal 6, D-12489 Berlin, Germany
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14
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Wang L, Beljonne D. Charge transport in organic semiconductors: Assessment of the mean field theory in the hopping regime. J Chem Phys 2013; 139:064316. [DOI: 10.1063/1.4817856] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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15
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Wang L, Beljonne D. Flexible Surface Hopping Approach to Model the Crossover from Hopping to Band-like Transport in Organic Crystals. J Phys Chem Lett 2013; 4:1888-1894. [PMID: 26283125 DOI: 10.1021/jz400871j] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Two distinct pictures are usually evoked when modeling charge transport in organic crystals, that is, band and hopping models, the signature of which is conveyed by a characteristic temperature dependence of mobility. Here, we present a novel flexible surface hopping approach compliant with general Hamiltonians that is able to grasp the crossover from hopping to band-like transport regimes. This approach is applied to solve a one-dimensional mixed quantum-classical model and to calculate the temperature dependence of charge mobility along with the degree of charge spatial localization. It is found that the roles of both local and nonlocal electron-phonon couplings strongly depend on the intrinsic charge localization strength.
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Affiliation(s)
- Linjun Wang
- Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, B-7000 Mons, Belgium
| | - David Beljonne
- Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, B-7000 Mons, Belgium
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16
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17
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Chen D, Ye J, Zhang H, Zhao Y. On the Munn−Silbey Approach to Polaron Transport with Off-Diagonal Coupling and Temperature-Dependent Canonical Transformations. J Phys Chem B 2011; 115:5312-21. [DOI: 10.1021/jp1093492] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dongmeng Chen
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798
- College of Physics Science and Technology, China University of Petroleum, Dongying 257061, China
| | - Jun Ye
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798
| | - Haijun Zhang
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798
| | - Yang Zhao
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798
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18
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Burtman V, Zelichonok A, Pakoulev AV. Molecular photovoltaics in nanoscale dimension. Int J Mol Sci 2011; 12:173-225. [PMID: 21339983 PMCID: PMC3039949 DOI: 10.3390/ijms12010173] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 12/01/2010] [Accepted: 12/15/2010] [Indexed: 11/16/2022] Open
Abstract
This review focuses on the intrinsic charge transport in organic photovoltaic (PVC) devices and field-effect transistors (SAM-OFETs) fabricated by vapor phase molecular self-assembly (VP-SAM) method. The dynamics of charge transport are determined and used to clarify a transport mechanism. The 1,4,5,8-naphthalene-tetracarboxylic diphenylimide (NTCDI) SAM devices provide a useful tool to study the fundamentals of polaronic transport at organic surfaces and to discuss the performance of organic photovoltaic devices in nanoscale. Time-resolved photovoltaic studies allow us to separate the charge annihilation kinetics in the conductive NTCDI channel from the overall charge kinetic in a SAM-OFET device. It has been demonstrated that tuning of the type of conductivity in NTCDI SAM-OFET devices is possible by changing Si substrate doping. Our study of the polaron charge transfer in organic materials proposes that a cation-radical exchange (redox) mechanism is the major transport mechanism in the studied SAM-PVC devices. The role and contribution of the transport through delocalized states of redox active surface molecular aggregates of NTCDI are exposed and investigated. This example of technological development is used to highlight the significance of future technological development of nanotechnologies and to appreciate a structure-property paradigm in organic nanostructures.
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Affiliation(s)
- Vladimir Burtman
- Department of Geology and Geophysics, University of Utah, 115 South 1460 East, Room 383, Salt Lake City, UT 84112, USA
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19
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Ortmann F, Bechstedt F, Hannewald K. Characteristics of small- and large-polaron motion in organic crystals. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:465802. [PMID: 21403376 DOI: 10.1088/0953-8984/22/46/465802] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Based on a generalized theory of charge transport in organic crystals we investigate the motion of polarons of arbitrary size. Within this theory, we analyze the influence of characteristic electronic, vibronic, and thermal energies and their role for the transport regimes. The polaron bandwidth is identified as the central temperature-dependent quantity. The size of the dressed charge carriers is used to analyze the correlation between the polaron size and transport mechanism. In addition, we propose that the band and hopping transport can be distinguished by investigating the mobility anisotropy. To do this only electronic structure parameters are necessary for comparison.
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20
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Fratini S, Ciuchi S. Bandlike motion and mobility saturation in organic molecular semiconductors. PHYSICAL REVIEW LETTERS 2009; 103:266601. [PMID: 20366327 DOI: 10.1103/physrevlett.103.266601] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Indexed: 05/29/2023]
Abstract
We analyze a model that accounts for the inherently large thermal lattice fluctuations associated with the weak van der Waals intermolecular bonding in crystalline organic semiconductors. In these materials the charge mobility generally exhibits a "metalliclike" power-law behavior, with no sign of thermally activated hopping characteristic of carrier self-localization, despite apparent mean free paths comparable to or lower than the intermolecular spacing. Our results show that such a puzzling transport regime can be understood from the simultaneous presence of band carriers and incoherent states that are dynamically localized by the thermal lattice disorder.
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Affiliation(s)
- S Fratini
- Institut Néel-CNRS and Université Joseph Fourier BP 166, F-38042 Grenoble Cedex 9, France
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21
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Cheung DL, Troisi A. Modelling charge transport in organic semiconductors: from quantum dynamics to soft matter. Phys Chem Chem Phys 2008; 10:5941-52. [PMID: 18825280 DOI: 10.1039/b807750a] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The charge carrier dynamics in organic semiconductors has been traditionally discussed with the models used in inorganic crystalline and amorphous solids but this analogy has severe limitations because of the more complicated role of nuclear motions in organic materials. In this perspective, we discuss how a new approach to the modelling of charge transport is emerging from the alliance between the conventional quantum chemical methods and the methods more traditionally used in soft-matter modelling. After describing the conventional limit cases of charge transport we discuss the problems arising from the comparison of the theory with the experimental and computational results. Several recent applications of numerical methods based on the propagation of the wavefunction or kinetic Monte Carlo methods on soft semiconducting materials are reviewed.
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Affiliation(s)
- David L Cheung
- Department of Chemistry and Centre of Scientific Computing, University of Warwick, Coventry, UK
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22
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Paganelli S, Ciuchi S. Charge transfer and coherence dynamics of a tunnelling system coupled to an harmonic oscillator. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2008; 20:235203. [PMID: 21694294 DOI: 10.1088/0953-8984/20/23/235203] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We study the transition probability and coherence of a two-site system, interacting with an oscillator. Both properties depend on the initial preparation. The oscillator is prepared in a thermal state and, even though it cannot be considered as an extended bath, it produces decoherence because of the large number of states involved in the dynamics. In the case in which the oscillator is initially displaced, a coherent dynamics of charge entangled with oscillator modes takes place. Coherency is, however, degraded as far as the oscillator mass increases, producing an increasingly large recoherence time. Calculations are carried on by exact diagonalization and compared with two semiclassical approximations. The role of the quantum effects are highlighted in the long time dynamics, where semiclassical approaches give rise to a dissipative behaviour. Moreover, we find that the oscillator dynamics has to be taken into account, even in a semiclassical approximation, in order to reproduce a thermally activated enhancement of the transition probability.
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Affiliation(s)
- S Paganelli
- Dipartimento di Fisica and CNISM, Università dell'Aquila, Via Vetoio, I-67100 L'Aquila, Italy. SMC Research Centre, INFM-CNR, Roma, Italy
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23
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Chapter 7 Quantum transport in quasicrystals and complex metallic alloys. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/s1570-002x(08)80022-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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24
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Coropceanu V, Cornil J, da Silva Filho DA, Olivier Y, Silbey R, Brédas JL. Charge transport in organic semiconductors. Chem Rev 2007; 107:926-52. [PMID: 17378615 DOI: 10.1021/cr050140x] [Citation(s) in RCA: 2048] [Impact Index Per Article: 120.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Veaceslav Coropceanu
- School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
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25
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Calhoun MF, Hsieh C, Podzorov V. Effect of interfacial shallow traps on polaron transport at the surface of organic semiconductors. PHYSICAL REVIEW LETTERS 2007; 98:096402. [PMID: 17359181 DOI: 10.1103/physrevlett.98.096402] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Indexed: 05/13/2023]
Abstract
The photo-induced electron and hole transfer across the semiconductor-dielectric interface in trap-dominated p-type organic field-effect transistors has been investigated. It has been observed that the transfer of electrons into the dielectric results in a decrease of the field-effect mobility of polarons, suggesting that additional shallow traps are generated in the conduction channel. Using this effect, the dependence of the field-effect mobility on the density of shallow traps, mu(N), has been measured, which allowed us to estimate the average polaron trapping time, tau_{tr}=50+/-10 ps, and the density of shallow traps, N0=(3+/-0.5) x 10(11) cm(-2), in the channel of single-crystal tetracene devices.
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Affiliation(s)
- M F Calhoun
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey, USA
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26
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Paganelli S, Ciuchi S. Tunnelling system coupled to a harmonic oscillator: an analytical treatment. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2006; 18:7669-7685. [PMID: 21690879 DOI: 10.1088/0953-8984/18/32/015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We give an analytical formula in term of continued fraction expansions for the spectral function of a tunnelling electron, coupled to a local lattice oscillation, in a two-site cluster at non-zero temperature. We also study the spectral function of the polaron, a better defined quasi-particle in the anti-adiabatic regime and at sufficiently low temperature. The exact results obtained allow us to look into a wide range of temperature and coupling. Asymptotic results can be obtained directly from the continued fraction expansions in both adiabatic and anti-adiabatic regimes. In the intermediate/strong anti-adiabatic case, in contrast to the usual Lang-Firsov approximation scheme, we found that there is no shrinking of the polaron band as temperature increases. Polaron bandwidth gets broader by temperature effects.
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Affiliation(s)
- S Paganelli
- Dipartimento di Fisica, Università di Roma La Sapienza, P. A. Moro 2, I-00185 Rome, Italy
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27
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Troisi A. Charge dynamics through pi-stacked arrays of conjugated molecules: effect of dynamic disorder in different transport/transfer regimes. MOLECULAR SIMULATION 2006. [DOI: 10.1080/08927020600857305] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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28
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Trambly de Laissardière G, Julien JP, Mayou D. Quantum transport of slow charge carriers in quasicrystals and correlated systems. PHYSICAL REVIEW LETTERS 2006; 97:026601. [PMID: 16907468 DOI: 10.1103/physrevlett.97.026601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2006] [Indexed: 05/11/2023]
Abstract
We show that the semiclassical model of conduction breaks down if the mean free path of charge carriers is smaller than a typical extension of their wave function. This situation is realized for sufficiently slow charge carriers and leads to a transition from a metalliclike to an insulatinglike regime when scattering by defects increases. This explains the unconventional conduction properties of quasicrystals and related alloys. The conduction properties of some heavy fermions or polaronic systems, where charge carriers are also slow, present a deep analogy.
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Affiliation(s)
- Guy Trambly de Laissardière
- Laboratoire de Physique Théorique et Modélisation, CNRS/Université de Cergy-Pontoise, 2 avenue A. Chauvin, 95302 Cergy-Pontoise, France
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29
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Kolodiazhnyi T, Wimbush SC. Spin-singlet small bipolarons in Nb-doped BaTiO3. PHYSICAL REVIEW LETTERS 2006; 96:246404. [PMID: 16907262 DOI: 10.1103/physrevlett.96.246404] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2005] [Indexed: 05/11/2023]
Abstract
The magnetic susceptibility and the electrical resistivity of n-type BaTi1-xNbxO3 have been measured over a wide temperature range. It is found that, for 0<x<0.2, dopant electrons form immobile spin-singlet small bipolarons with binding energy around 110 meV. For x=0.2, a maximum in the electrical resistivity around 15 K indicates a crossover from band to hopping transport of the charge carriers, a phenomenon expected but rarely observed in real polaronic systems.
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Affiliation(s)
- T Kolodiazhnyi
- ICYS, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
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30
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Troisi A, Orlandi G. Band Structure of the Four Pentacene Polymorphs and Effect on the Hole Mobility at Low Temperature. J Phys Chem B 2005; 109:1849-56. [PMID: 16851167 DOI: 10.1021/jp0457489] [Citation(s) in RCA: 153] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The band structure of the four known polymorphs of pentacene is computed from first principles using the accurate molecular orbitals of the isolated molecule as the basis for the calculation of the crystalline orbitals. The computed bands are remarkably different for each polymorph, but their diversity can be easily rationalized using a simple analytical model that employs only three parameters. The effect of the electronic structure on the hole mobility was evaluated using a simple model based on the constant relaxation time approximation. It is found that the mobility tensor is highly anisotropic for three of the four considered polymorphs. The practical implication of this prediction on the technology of thin-film organic transistors is discussed.
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Affiliation(s)
- Alessandro Troisi
- Dipartimento di Chimica "G. Ciamician", Universita di Bologna, via F. Selmi 2, 40126 Bologna, Italy
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