1
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Rasool S, Yeop J, An NG, Kim JW, Kim JY. Role of Charge-Carrier Dynamics Toward the Fabrication of Efficient Air-Processed Organic Solar Cells. SMALL METHODS 2024; 8:e2300578. [PMID: 37649231 DOI: 10.1002/smtd.202300578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 08/10/2023] [Indexed: 09/01/2023]
Abstract
Over the past couple of decades, immense research has been carried out to understand the photo-physics of an organic solar cell (OSC) that is important to enhance its efficiency and stability. Since OSCs undergoes complex photophysical phenomenon, studying these factors has led to designing new materials and implementing new strategies to improve efficiency in OSCs. In this regard, the invention of the non-fullerene acceptorshas greatly revolutionized the understanding of the fundamental processes occurring in OSCs. However, such vital fundamental research from device physics perspectives is carried out on glovebox (GB) processed OSCs and there is a scarcity of research on air-processed (AP) OSCs. This review will focus on charge carrier dynamics such as exciton diffusion, exciton dissociation, charge-transfer states, significance of highest occupied molecular orbital-offsets, and hole-transfer efficiencies of GB-OSCs and compare them with the available data from the AP-OSCs. Finally, key requirements for the fabrication of efficient AP-OSCs will be presented from a charge-carrier dynamics perspective. The key aspects from the charge-carrier dynamics view to fabricate efficient OSCs either from GB or air are provided.
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Affiliation(s)
- Shafket Rasool
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, South Korea
| | - Jiwoo Yeop
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, South Korea
| | - Na Gyeong An
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, South Korea
- Department of Chemical and Biological Engineering, Monash University, Victoria, 3800, Australia
- Commonwealth Scientific and Industrial Research Organization (CSIRO) Manufacturing, Clayton, Victoria, 3168, Australia
| | - Jae Won Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, South Korea
| | - Jin Young Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, South Korea
- Graduate School of Carbon Neutrality, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, South Korea
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2
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Rasool S, Kim JY. Prospects of glove-box versus air-processed organic solar cells. Phys Chem Chem Phys 2023; 25:19337-19357. [PMID: 37462029 DOI: 10.1039/d3cp02591h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
In the search for alternate green energy sources to offset dependence on fossil fuels, solar energy can certainly meet two needs with one deed: fulfil growing global energy demands due to its non-depletable nature and lower greenhouse gas emissions. As such, third generation thin film photovoltaic technology based organic solar cells (OSCs) can certainly play their role in providing electricity at a competing or lower cost than 1st and 2nd generation solar technologies. As OSCs are still at an early stage of research and development, much focus has been placed on improving power conversion efficiencies (PCEs) inside a controlled environment i.e. a glove-box (GB) filled with an inert gas such as N2. This was necessary until now, to control and study the local nanomorphology of the spin-coated blend films. For OSCs to compete with other solar energy technologies, OSCs should produce similar or even better morphologies in an open environment i.e. air, such that air-processed OSCs can result in similar PCEs in comparison to their GB-processed counterparts. In this review, we have compared GB- vs. air-processed OSCs from morphological and device physics aspects and underline the key features of efficient OSCs, processed in either GB or air.
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Affiliation(s)
- Shafket Rasool
- Graduate School of Carbon Neutrality, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea.
| | - Jin Young Kim
- Graduate School of Carbon Neutrality, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea.
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3
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Natsuda SI, Saito T, Shirouchi R, Imakita K, Tamai Y. Delocalization suppresses nonradiative charge recombination in polymer solar cells. Polym J 2022. [DOI: 10.1038/s41428-022-00685-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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5
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Gibbons DJ, Farawar A, Mazzella P, Leroy-Lhez S, Williams RM. Making triplets from photo-generated charges: observations, mechanisms and theory. Photochem Photobiol Sci 2020; 19:136-158. [DOI: 10.1039/c9pp00399a] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Photo-excitation of electron donor–acceptor systems can lead to the generation of a charge separated state (CT). Sometimes the charge recombination occurs mainly to the local triplet excited state (T1). How does the spin flip?
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Affiliation(s)
- Dáire J. Gibbons
- Molecular Photonics Group
- Van't Hoff Institute for Molecular Sciences (HIMS)
- Universiteit van Amsterdam
- 1098 XH Amsterdam
- Netherlands
| | - Aram Farawar
- Molecular Photonics Group
- Van't Hoff Institute for Molecular Sciences (HIMS)
- Universiteit van Amsterdam
- 1098 XH Amsterdam
- Netherlands
| | - Paul Mazzella
- Molecular Photonics Group
- Van't Hoff Institute for Molecular Sciences (HIMS)
- Universiteit van Amsterdam
- 1098 XH Amsterdam
- Netherlands
| | - Stéphanie Leroy-Lhez
- PEIRENE – EA7500
- Faculty of Sciences and Technology – University of Limoges
- 87060 Limoges
- France
| | - René M. Williams
- Molecular Photonics Group
- Van't Hoff Institute for Molecular Sciences (HIMS)
- Universiteit van Amsterdam
- 1098 XH Amsterdam
- Netherlands
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6
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Midori K, Fukuhara T, Tamai Y, Do Kim H, Ohkita H. Enhanced Hole Transport in Ternary Blend Polymer Solar Cells. Chemphyschem 2019; 20:2683-2688. [PMID: 31077528 DOI: 10.1002/cphc.201900343] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/06/2019] [Indexed: 11/11/2022]
Abstract
Recently, ternary blend polymer solar cells have attracted great attention to improve a short-circuit current density (JSC ) effectively, because complementary absorption bands can harvest the solar light over a wide wavelength range from visible to near-IR region. Interestingly, some ternary blend solar cells have shown improvements not only in JSC but also in fill factor (FF). Previously, we also reported that a ternary blend solar cell based on a low-bandgap polymer (PTB7-Th), a wide-bandgap polymer (PDCBT), and a fullerene derivative (PCBM) exhibited a higher FF than their binary analogues. Herein, we study charge transport in PTB7-Th/PDCBT/PCBM ternary blend films to address the origin of the improvement in FF. We found that hole polarons are located in PTB7-Th domains and their mobility is enhanced in the ternary blend film.
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Affiliation(s)
- Koshiro Midori
- Department of Polymer Chemistry Graduate School of Engineering, Kyoto University Katsura, Nishikyo-ku, 615-8510, Kyoto, Japan
| | - Tomohiro Fukuhara
- Department of Polymer Chemistry Graduate School of Engineering, Kyoto University Katsura, Nishikyo-ku, 615-8510, Kyoto, Japan
| | - Yasunari Tamai
- Department of Polymer Chemistry Graduate School of Engineering, Kyoto University Katsura, Nishikyo-ku, 615-8510, Kyoto, Japan.,PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Hyung Do Kim
- Department of Polymer Chemistry Graduate School of Engineering, Kyoto University Katsura, Nishikyo-ku, 615-8510, Kyoto, Japan
| | - Hideo Ohkita
- Department of Polymer Chemistry Graduate School of Engineering, Kyoto University Katsura, Nishikyo-ku, 615-8510, Kyoto, Japan
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7
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Xu J, Tong X, Yu P, Wenya GE, McGrath T, Fong MJ, Wu J, Wang ZM. Ultrafast Dynamics of Charge Transfer and Photochemical Reactions in Solar Energy Conversion. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2018; 5:1800221. [PMID: 30581691 PMCID: PMC6299728 DOI: 10.1002/advs.201800221] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 08/05/2018] [Indexed: 05/31/2023]
Abstract
For decades, ultrafast time-resolved spectroscopy has found its way into an increasing number of applications. It has become a vital technique to investigate energy conversion processes and charge transfer dynamics in optoelectronic systems such as solar cells and solar-driven photocatalytic applications. The understanding of charge transfer and photochemical reactions can help optimize and improve the performance of relevant devices with solar energy conversion processes. Here, the fundamental principles of photochemical and photophysical processes in photoinduced reactions, in which the fundamental charge carrier dynamic processes include interfacial electron transfer, singlet excitons, triplet excitons, excitons fission, and recombination, are reviewed. Transient absorption (TA) spectroscopy techniques provide a good understanding of the energy/electron transfer processes. These processes, including excited state generation and interfacial energy/electron transfer, are dominate constituents of solar energy conversion applications, for example, dye-sensitized solar cells and photocatalysis. An outlook for intrinsic electron/energy transfer dynamics via TA spectroscopic characterization is provided, establishing a foundation for the rational design of solar energy conversion devices.
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Affiliation(s)
- Jing‐Yin Xu
- Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu610054P. R. China
| | - Xin Tong
- Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu610054P. R. China
| | - Peng Yu
- Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu610054P. R. China
| | - Gideon Evans Wenya
- Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu610054P. R. China
| | - Thomas McGrath
- Department of PhysicsLancaster UniversityLancasterLancashireLA14YWUK
| | | | - Jiang Wu
- Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu610054P. R. China
- Department of Electronic and Electrical EngineeringUniversity College LondonTorrington PlaceLondonWC1E7JEUK
| | - Zhiming M. Wang
- Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu610054P. R. China
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8
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Yan Y, Song L, Shi Q. Understanding the free energy barrier and multiple timescale dynamics of charge separation in organic photovoltaic cells. J Chem Phys 2018; 148:084109. [DOI: 10.1063/1.5017866] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Yaming Yan
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, China and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Linze Song
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, China and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiang Shi
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, China and University of Chinese Academy of Sciences, Beijing 100049, China
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9
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Shimazaki T, Tashiro M, Nakajima T. Theoretical study on mesoscopic-size impurity effects in the charge separation process of organic photocells. Phys Chem Chem Phys 2018; 20:14846-14854. [DOI: 10.1039/c7cp08125a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A bulk-heterojunction structure is often employed to develop high-performance organic photocells, in which the donor and acceptor regions are complexly intertwined.
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Affiliation(s)
- Tomomi Shimazaki
- Kobe University
- Graduate School of System Informatics
- Kobe 657-8501
- Japan
- RIKEN
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10
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Tamai Y, Fan Y, Kim VO, Ziabrev K, Rao A, Barlow S, Marder SR, Friend RH, Menke SM. Ultrafast Long-Range Charge Separation in Nonfullerene Organic Solar Cells. ACS NANO 2017; 11:12473-12481. [PMID: 29148715 DOI: 10.1021/acsnano.7b06575] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Rapid, long-range charge separation in polymer-fullerene organic solar cells (OSCs) enables electrons and holes to move beyond their Coulomb capture radius and overcome geminate recombination. Understanding the nature of charge generation and recombination mechanisms in efficient, nonfullerene-acceptor-based OSCs are critical to further improve device performance. Here we report charge dynamics in an OSC using a perylene diimide (PDI) dimer acceptor. We use transient absorption spectroscopy to track the time evolution of electroabsorption caused by the dipolar electric field generated between electron-hole pairs as they separate after ionization at the donor-acceptor interface. We show that charges separate rapidly (<1 ps) and that free charge carriers are generated very efficiently (∼90% quantum yield). However, in the PDI-based OSC, external charge extraction is impaired by faster nongeminate decay to the ground state and to lower-lying triplet states.
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Affiliation(s)
- Yasunari Tamai
- Cavendish Laboratory, Department of Physics, University of Cambridge , Cambridge CB3 0HE, United Kingdom
| | - Yeli Fan
- Center for Organic Photonics and Electronics and School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States
| | - Vincent O Kim
- Cavendish Laboratory, Department of Physics, University of Cambridge , Cambridge CB3 0HE, United Kingdom
| | - Kostiantyn Ziabrev
- Center for Organic Photonics and Electronics and School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States
| | - Akshay Rao
- Cavendish Laboratory, Department of Physics, University of Cambridge , Cambridge CB3 0HE, United Kingdom
| | - Stephen Barlow
- Center for Organic Photonics and Electronics and School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States
| | - Seth R Marder
- Center for Organic Photonics and Electronics and School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States
| | - Richard H Friend
- Cavendish Laboratory, Department of Physics, University of Cambridge , Cambridge CB3 0HE, United Kingdom
| | - S Matthew Menke
- Cavendish Laboratory, Department of Physics, University of Cambridge , Cambridge CB3 0HE, United Kingdom
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11
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Nakano K, Tajima K. Organic Planar Heterojunctions: From Models for Interfaces in Bulk Heterojunctions to High-Performance Solar Cells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1603269. [PMID: 27885716 DOI: 10.1002/adma.201603269] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/30/2016] [Indexed: 05/28/2023]
Abstract
Recent progress regarding planar heterojunctions (PHJs) is reviewed, with respect to the fundamental understanding of the photophysical processes at the donor/acceptor interfaces in organic photovoltaic devices (OPVs). The current state of OPV research is summarized and the advantages of PHJs as models for exploring the relationship between organic interfaces and device characteristics described. The preparation methods and the characterization of PHJ structures to provide key points for the appropriate handling of PHJs. Next, we describe the effects of the donor/acceptor interface on each photoelectric conversion process are reviewed by examining various PHJ systems to clarify what is currently known and not known. Finally, it is discussed how we the knowledge obtained by studies of PHJs can be used to overcome the current limits of OPV efficiency.
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Affiliation(s)
- Kyohei Nakano
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Keisuke Tajima
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
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12
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TAMAI Y. Exciton and Charge Dynamics in Polymer Solar Cells. KOBUNSHI RONBUNSHU 2017. [DOI: 10.1295/koron.2017-0028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Yasunari TAMAI
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University
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13
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Solanki A, Bagui A, Long G, Wu B, Salim T, Chen Y, Lam YM, Sum TC. Effectiveness of External Electric Field Treatment of Conjugated Polymers in Bulk-Heterojunction Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2016; 8:32282-32291. [PMID: 27618844 DOI: 10.1021/acsami.6b08012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
External electric field treatment (EFT) on P3HT:PCBM bulk heterojunction (BHJ) devices was recently found to be a viable approach for improving the power conversion efficiencies (PCEs) through modulating the blend nanomorphology. However, its effectiveness over the broad family of polymer-fullerene blends remains unclear. Herein, we investigate the effects of external EFT on various polymer-fullerene blends with distinct morphologies stemming from the difference in molecular structure of the polymers (i.e., semicrystalline vs amorphous) in a bid to establish a clear morphology-function-charge dynamics relationship to the photovoltaic performance. Our findings reveal that EFT promotes self-organization of the semicrystalline thiophene-based conjugated polymers (i.e., P3HT and P3BT) while it was ineffective for the amorphous polymers (i.e., PTB7 and PCPDTBT) even at the maximum applied E-field of 8 kV cm-1. Transient absorption spectroscopy shows an improvement in the initial charge-carrier and polaron formation from delocalized excitons in the E-field treated semicrystalline blends compared to their untreated reference samples. Interfacial trap-assisted monomolecular and trap-free bimolecular recombination at nanosecond-microsecond time scale in the E-field treated P3BT:PC60BM devices are significantly suppressed. Importantly, our findings shed new light and provide guidelines on the effectiveness of utilizing external EFT to enhance the PCEs of a larger family of conjugated polymer-based BHJ OSCs.
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Affiliation(s)
- Ankur Solanki
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371
| | - Anirban Bagui
- Department of Physics, Indian Institute of Technology Kanpur , Kanpur 208016, India
| | - Guankui Long
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071, China
- School of Materials Science and Engineering, Nankai University , Tianjin 300071, China
| | - Bo Wu
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371
| | - Teddy Salim
- School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798
| | - Yongsheng Chen
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300071, China
- School of Materials Science and Engineering, Nankai University , Tianjin 300071, China
| | - Yeng Ming Lam
- School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798
- Energy Research Institute @ NTU (ERI@N) , 1 CleanTech Loop, #06-04 CleanTech One, Singapore 637141
| | - Tze Chien Sum
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371
- Energy Research Institute @ NTU (ERI@N) , 1 CleanTech Loop, #06-04 CleanTech One, Singapore 637141
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14
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Kawashima K, Fukuhara T, Suda Y, Suzuki Y, Koganezawa T, Yoshida H, Ohkita H, Osaka I, Takimiya K. Implication of Fluorine Atom on Electronic Properties, Ordering Structures, and Photovoltaic Performance in Naphthobisthiadiazole-Based Semiconducting Polymers. J Am Chem Soc 2016; 138:10265-75. [DOI: 10.1021/jacs.6b05418] [Citation(s) in RCA: 287] [Impact Index Per Article: 35.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Kazuaki Kawashima
- Department
of Applied Chemistry, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Tomohiro Fukuhara
- Department
of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Kyoto 615-8510, Japan
| | | | - Yasuhito Suzuki
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Tomoyuki Koganezawa
- Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | | | - Hideo Ohkita
- Department
of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Kyoto 615-8510, Japan
| | - Itaru Osaka
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kazuo Takimiya
- Department
of Applied Chemistry, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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15
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Shimazaki T, Nakajima T. Theoretical study on the cooperative exciton dissociation process based on dimensional and hot charge-transfer state effects in an organic photocell. J Chem Phys 2016; 144:234906. [DOI: 10.1063/1.4953905] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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16
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Kawashima K, Tamai Y, Ohkita H, Osaka I, Takimiya K. High-efficiency polymer solar cells with small photon energy loss. Nat Commun 2015; 6:10085. [PMID: 26626042 PMCID: PMC4686756 DOI: 10.1038/ncomms10085] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 11/02/2015] [Indexed: 12/23/2022] Open
Abstract
A crucial issue facing polymer-based solar cells is how to manage the energetics of the polymer/fullerene blends to maximize short-circuit current density and open-circuit voltage at the same time and thus the power conversion efficiency. Here we demonstrate that the use of a naphthobisoxadiazole-based polymer with a narrow bandgap of 1.52 eV leads to high open-circuit voltages of approximately 1 V and high-power conversion efficiencies of ∼9% in solar cells, resulting in photon energy loss as small as ∼0.5 eV, which is much smaller than that of typical polymer systems (0.7-1.0 eV). This is ascribed to the high external quantum efficiency for the systems with a very small energy offset for charge separation. These unconventional features of the present polymer system will inspire the field of polymer-based solar cells towards further improvement of power conversion efficiencies with both high short-circuit current density and open-circuit voltage.
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Affiliation(s)
- Kazuaki Kawashima
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan.,RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yasunari Tamai
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Kyoto 615-8510, Japan
| | - Hideo Ohkita
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Kyoto 615-8510, Japan.,Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Tokyo 102-0075, Japan
| | - Itaru Osaka
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.,Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Tokyo 102-0075, Japan
| | - Kazuo Takimiya
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan.,RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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17
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Tamai Y, Ohkita H, Benten H, Ito S. Exciton Diffusion in Conjugated Polymers: From Fundamental Understanding to Improvement in Photovoltaic Conversion Efficiency. J Phys Chem Lett 2015; 6:3417-28. [PMID: 26269208 DOI: 10.1021/acs.jpclett.5b01147] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Singlet exciton diffusion plays a central role in the photovoltaic conversion in organic photovoltaics (OPVs). Upon light absorption, singlet excitons are promptly generated in organic materials instead of charge carriers because the dielectric constant (εr) is small (∼3-4), which is in sharp contrast to inorganic and perovskite solar cells. In order to convert to charge carriers, excitons need to diffuse into an interface between electron donor and acceptor materials before deactivating to the ground state. Therefore, fundamental understanding of exciton diffusion dynamics is one of the most important issues to further improve OPVs. We highlight recent leading studies in this field and describe several approaches for efficient exciton harvesting at the interface in OPVs.
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Affiliation(s)
- Yasunari Tamai
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University , Katsura, Nishikyo, Kyoto 615-8510, Japan
| | - Hideo Ohkita
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University , Katsura, Nishikyo, Kyoto 615-8510, Japan
- Japan Science and Technology Agency (JST), PRESTO, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
| | - Hiroaki Benten
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University , Katsura, Nishikyo, Kyoto 615-8510, Japan
| | - Shinzaburo Ito
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University , Katsura, Nishikyo, Kyoto 615-8510, Japan
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18
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Gehrig DW, Howard IA, Sweetnam S, Burke TM, McGehee MD, Laquai F. The Impact of Donor-Acceptor Phase Separation on the Charge Carrier Dynamics in pBTTT:PCBM Photovoltaic Blends. Macromol Rapid Commun 2015; 36:1054-60. [DOI: 10.1002/marc.201500112] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 03/11/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Dominik W. Gehrig
- Max Planck Research Group for Organic Optoelectronics; Max Planck Institute for Polymer Research; Ackermannweg 10 D-55128 Mainz Germany
| | - Ian A. Howard
- Institute of Microstructure Technology (IMT); Karlsruhe Institute of Technology (KIT); Hermann-von-Helmholtz-Platz 1 D-76344 Eggenstein-Leopoldshafen Germany
| | - Sean Sweetnam
- Materials Science and Engineering; Stanford University; 476 Lomita Mall Stanford CA 94305-4045 USA
| | - Timothy M. Burke
- Materials Science and Engineering; Stanford University; 476 Lomita Mall Stanford CA 94305-4045 USA
| | - Michael D. McGehee
- Materials Science and Engineering; Stanford University; 476 Lomita Mall Stanford CA 94305-4045 USA
| | - Frédéric Laquai
- Max Planck Research Group for Organic Optoelectronics; Max Planck Institute for Polymer Research; Ackermannweg 10 D-55128 Mainz Germany
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19
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Yoshikawa S, Saeki A, Saito M, Osaka I, Seki S. On the role of local charge carrier mobility in the charge separation mechanism of organic photovoltaics. Phys Chem Chem Phys 2015; 17:17778-84. [DOI: 10.1039/c5cp01604e] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Although the charge separation (CS) and transport processes that compete with geminate and non-geminate recombination are commonly regarded as the governing factors of organic photovoltaic (OPV) efficiency, the details of the CS mechanism remain largely unexplored.
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Affiliation(s)
- Saya Yoshikawa
- Department of Applied Chemistry
- Graduate School of Engineering
- Osaka University
- Suita
- Japan
| | - Akinori Saeki
- Department of Applied Chemistry
- Graduate School of Engineering
- Osaka University
- Suita
- Japan
| | - Masahiko Saito
- Emergent Molecular Function Research Group
- RIKEN Center for Emergent Matter Science (CEMS)
- Wako
- Japan
| | - Itaru Osaka
- Japan Science and Technology Agency (JST)-PRESTO
- Japan
- Emergent Molecular Function Research Group
- RIKEN Center for Emergent Matter Science (CEMS)
- Wako
| | - Shu Seki
- Department of Applied Chemistry
- Graduate School of Engineering
- Osaka University
- Suita
- Japan
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20
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Wang Y, Ohkita H, Benten H, Ito S. Highly efficient exciton harvesting and charge transport in ternary blend solar cells based on wide- and low-bandgap polymers. Phys Chem Chem Phys 2015; 17:27217-24. [DOI: 10.1039/c5cp05161d] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Ternary blend solar cells using a crystalline wide-bandgap P3HT and a low-bandgap PSBTBT exhibit good exciton harvesting and charge transport.
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Affiliation(s)
- Yanbin Wang
- Department of Polymer Chemistry
- Graduate School of Engineering
- Kyoto University
- Nishikyo
- Japan
| | - Hideo Ohkita
- Department of Polymer Chemistry
- Graduate School of Engineering
- Kyoto University
- Nishikyo
- Japan
| | - Hiroaki Benten
- Department of Polymer Chemistry
- Graduate School of Engineering
- Kyoto University
- Nishikyo
- Japan
| | - Shinzaburo Ito
- Department of Polymer Chemistry
- Graduate School of Engineering
- Kyoto University
- Nishikyo
- Japan
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21
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Shimazaki T, Nakajima T. Theoretical study of exciton dissociation through hot states at donor–acceptor interface in organic photocell. Phys Chem Chem Phys 2015; 17:12538-44. [DOI: 10.1039/c5cp00740b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We theoretically study the dissociation of geminate electron–hole pairs (i.e., excitons) through vibrational hot states at the donor–acceptor interface of organic photocells.
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