Light-Harvesting Mechanism in Polymer/Fullerene/Dye Ternary Blends Studied by Transient Absorption Spectroscopy

被引:114
作者
Honda, Satoshi [1 ]
Yokoya, Seiichirou [1 ]
Ohkita, Hideo [1 ,2 ]
Benten, Hiroaki [1 ]
Ito, Shinzaburo [1 ]
机构
[1] Kyoto Univ, Grad Sch Engn, Dept Polymer Chem, Nishikyo Ku, Kyoto 6158510, Japan
[2] Japan Sci & Technol Agcy JST, PRESTO, Kawaguchi, Saitama 3320012, Japan
关键词
POLYMER SOLAR-CELLS; ENERGY-TRANSFER; CARRIER GENERATION; CHARGE GENERATION; MORPHOLOGY; EFFICIENCY; FILMS; DYE; ORGANIZATION; DYNAMICS;
D O I
10.1021/jp201742v
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The light-harvesting mechanism in polymer:fullerene:dye ternary blends was comprehensively studied by transient absorption spectroscopy. The ternary blend films consist of poly(3-hexylthiophene) (P3HT), a fullerene derivative (PCBM), and a silicon phthalocyanine derivative (SiPc) as a light-harvesting dye. Upon dye excitation of P3HT:PCBM: SiPc blends, P3HT polarons and SiPc anions were generated from SiPc excitons, and then electrons were shifted from SiPc to PCBM, suggesting that SiPc molecules are selectively located in a disordered P3HT matrix mixed with PCBM molecules at the P3HT/PCBM interface. Upon polymer excitation, P3HT excitons decayed more rapidly in ternary blends than in binary blends with an identically rapid formation of SiPc photobleaching, suggesting efficient energy transfer from P3HT to SiPc because of the large spectral overlap between P3HT emission and SiPc absorption, followed by slightly delayed generation of P3HT polarons and SiPc anions from SiPc excitons. Subsequently, the photobleaching disappeared while the P3HT polaron band remains unchanged, suggesting the charge shift from SiPc anion to PC BM. All these photovoltaic conversion processes are much more rapid than backward reactions, and therefore highly efficient light harvesting is achieved in ternary blend solar cells. This is because the SiPc molecules are selectively localized at the P3HT/PCBM interface with an interfacial coverage of 40%. Remarkably, the SiPc molecules are closely contact to both P3HT and PCBM at the interface in solvent-annealed ternary blends, which is an ideal interfacial structure for the efficient photovoltaic conversion.
引用
收藏
页码:11306 / 11317
页数:12
相关论文
共 50 条
[1]   Watching electrons move in real time: Ultrafast infrared spectroscopy of a polymer blend photovoltaic material [J].
Barbour, Larry W. ;
Hegadorn, Maureen ;
Asbury, John B. .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2007, 129 (51) :15884-15894
[2]   ON THE MECHANISM OF THE PRIMARY CHARGE SEPARATION IN BACTERIAL PHOTOSYNTHESIS [J].
BIXON, M ;
JORTNER, J ;
MICHELBEYERLE, ME .
BIOCHIMICA ET BIOPHYSICA ACTA, 1991, 1056 (03) :301-315
[3]   Solution-processed organic solar cells [J].
Brabec, Christoph J. ;
Durrant, James R. .
MRS BULLETIN, 2008, 33 (07) :670-675
[4]   Polymer-Fullerene Bulk-Heterojunction Solar Cells [J].
Brabec, Christoph J. ;
Gowrisanker, Srinivas ;
Halls, Jonathan J. M. ;
Laird, Darin ;
Jia, Shijun ;
Williams, Shawn P. .
ADVANCED MATERIALS, 2010, 22 (34) :3839-3856
[5]   Low band gap polymers for organic photovoltaics [J].
Bundgaard, Eva ;
Krebs, Frederik C. .
SOLAR ENERGY MATERIALS AND SOLAR CELLS, 2007, 91 (11) :954-985
[6]   Polymer solar cells with enhanced open-circuit voltage and efficiency [J].
Chen, Hsiang-Yu ;
Hou, Jianhui ;
Zhang, Shaoqing ;
Liang, Yongye ;
Yang, Guanwen ;
Yang, Yang ;
Yu, Luping ;
Wu, Yue ;
Li, Gang .
NATURE PHOTONICS, 2009, 3 (11) :649-653
[7]   Low-bandgap conjugated polymer for high efficient photovoltaic applications [J].
Chen, Yi-Chun ;
Yu, Chao-Ying ;
Fan, Yu-Ling ;
Hung, Ling-I ;
Chen, Chih-Ping ;
Ting, Ching .
CHEMICAL COMMUNICATIONS, 2010, 46 (35) :6503-6505
[8]   Role of intermolecular coupling in the photophysics of disordered organic semiconductors: Aggregate emission in regioregular polythiophene [J].
Clark, Jenny ;
Silva, Carlos ;
Friend, Richard H. ;
Spano, Frank C. .
PHYSICAL REVIEW LETTERS, 2007, 98 (20)
[9]   Determining exciton bandwidth and film microstructure in polythiophene films using linear absorption spectroscopy [J].
Clark, Jenny ;
Chang, Jui-Fen ;
Spano, Frank C. ;
Friend, Richard H. ;
Silva, Carlos .
APPLIED PHYSICS LETTERS, 2009, 94 (16)
[10]   Photovoltaic Charge Generation in Organic Semiconductors Based on Long-Range Energy Transfer [J].
Coffey, David C. ;
Ferguson, Andrew J. ;
Kopidakis, Nikos ;
Rumbles, Garry .
ACS NANO, 2010, 4 (09) :5437-5445