共 109 条
Bithiopheneimide-Dithienosilole/Dithienogermole Copolymers for Efficient Solar Cells: Information from Structure-Property-Device Performance Correlations and Comparison to Thieno[3,4-c]pyrrole-4,6-dione Analogues
被引:248
作者:
Guo, Xugang
[1
,2
]
Zhou, Nanjia
[2
,3
]
Lou, Sylvia J.
[1
,2
]
Hennek, Jonathan W.
[1
,2
]
Ponce Ortiz, Rocio
[1
,2
,4
]
Butler, Melanie R.
[1
,2
]
Boudreault, Pierre-Luc T.
[1
,2
]
Strzalka, Joseph
[5
]
Morin, Pierre-Olivier
[6
]
Leclerc, Mario
[6
]
Lopez Navarrete, Juan T.
[4
]
Ratner, Mark A.
[1
,2
]
Chen, Lin X.
[1
,2
]
Chang, Robert P. H.
[2
,3
]
Facchetti, Antonio
[1
,2
,3
,7
]
Marks, Tobin J.
[1
,2
,3
]
机构:
[1] Northwestern Univ, Dept Chem, Evanston, IL 60208 USA
[2] Northwestern Univ, Mat Res Ctr, Argonne NW Solar Energy Res Ctr, Evanston, IL 60208 USA
[3] Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA
[4] Univ Malaga, Dept Phys Chem, E-29071 Malaga, Spain
[5] Argonne Natl Lab, Xray Sci Div, Argonne, IL 60439 USA
[6] Univ Laval, Dept Chim, Quebec City, PQ G1V 0A6, Canada
[7] Polyera Corp, Skokie, IL 60077 USA
关键词:
LOW-BANDGAP POLYMERS;
MOLECULAR-ENERGY LEVEL;
SHORT-CIRCUIT CURRENT;
INDIUM TIN OXIDE;
CONJUGATED POLYMERS;
N-CHANNEL;
SEMICONDUCTING POLYMERS;
SYNTHETIC PRINCIPLES;
BUILDING-BLOCKS;
RATIONAL DESIGN;
D O I:
10.1021/ja3081583
中图分类号:
O6 [化学];
学科分类号:
0703 ;
摘要:
Rational creation of polymeric semiconductors from novel building blocks is critical to polymer solar cell (PSC) development. We report a new series of bithiopheneimide-based donor-acceptor copolymers for bulk-heterojunction (BHJ) PSCs. The bithiopheneimide electron deficiency compresses polymer bandgaps and lowers the HOMOs-essential to maximize power conversion efficiency (PCE). While the dithiophene bridge progression R2Si -> R2Ge minimally impacts bandgaps, it substantially alters the HOMO energies. Furthermore, imide N-substituent variation has negligible impact on polymer opto-electrical properties, but greatly affects solubility and microstructure. Grazing incidence wide-angle X-ray scattering (GIWAXS) indicates that branched N-alkyl substituents increased polymer pi-pi spacings vs linear N-alkyl substituents, and the dithienosilole-based PBTISi series exhibits more ordered packing than the dithienogermole-based PBTIGe analogues. Further insights into structure-property-device performance correlations are provided by a thieno[3,4-c]pyrrole-4,6-dione (TPD)-dithienosilole copolymer PTPDSi. DFT computation and optical spectroscopy show that the TPD-based polymers achieve greater subunit-subunit coplanarity via intramolecular (thienyl)S center dot center dot center dot O(carbonyl) interactions, and GIWAXS indicates that PBTISi-C8 has lower lamellar Ordering, but closer pi-pi Spacing than does the TPD-based analogue. Inverted BHJ solar cells using bithiopheneimide-based polymer as donor and PC71BM as acceptor exhibit promising device performance with PCEs up to 6.41% and V-oc > 0.80 V. In analogous cells, the TPD analogue exhibits 0.08 V higher V-oc with an enhanced PCE of 6.83%, mainly attributable to the lower-lying HOMO induced by the higher imide group density. These results demonstrate the potential of BTI-based polymers for high-performance solar cells, and provide generalizable insights into structure-property relationships in TPD, BTI, and related polymer semiconductors.
引用
收藏
页码:18427 / 18439
页数:13
相关论文