Benzodithiophene and Imide-Based Copolymers for Photovoltaic Applications

被引：58

作者：

Braunecker, Wade A. ^{[1
]}

Owczarczyk, Zbyslaw R. ^{[1
]}

Garcia, Andres ^{[1
]}

Kopidakis, Nikos ^{[1
]}

Larsen, Ross E. ^{[1
]}

Hammond, Scott R. ^{[1
]}

Ginley, David S. ^{[1
]}

Olson, Dana C. ^{[1
]}

机构：

[1] Natl Renewable Energy Lab, Golden, CO 80401 USA

来源：

CHEMISTRY OF MATERIALS | 2012年 / 24卷 / 07期

关键词：

pyrroledione; isoindoledione; benzodithiophene; solar cell; low band gap polymer; HETEROJUNCTION SOLAR-CELLS; LOW-BAND-GAP; SUBSTITUTED CONJUGATED POLYMERS; MOLECULAR-WEIGHT; CONVERSION EFFICIENCY; ORGANIC PHOTOVOLTAICS; PERFORMANCE; LEVEL; POLY(3-HEXYLTHIOPHENE); POLY(ISOTHIANAPHTHENE);

D O I：

10.1021/cm2038427

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：

Conjugated alternating copolymers were designed with low optical band gaps for organic photovoltaic (OPV) applications by considering quinoid resonance stabilization. Copolymers of thienoisoindoledione (TID) and benzodithiophene (BDT) had appreciably lower band gaps (by similar to 0.4 eV) than copolymers of thienopyrroledione (TPD) and BDT. In addition to intramolecular charge transfer stabilization (i.e., the "push-pull" effect), the former copolymer's quinoid resonance structure is stabilized by a gain in aromatic resonance energy in the isoindole unit. Additionally, the HOMO levels of the copolymers could be tuned with chemical modifications to the BDT monomer, resulting in open circuit voltages of greater than 1 V in photovoltaic devices. Despite the optimized band gap, TID containing polymers displayed lower photoconductance, as determined by time-resolved microwave conductivity, and decreased device efficiency (2.1% vs 4.8%) as compared with TPD analogues. These results were partially attributed to morphology, as computational modeling suggests TID copolymers have a twisted backbone, and X-ray diffraction data indicate the polymer films do not form ordered domains, whereas TPD copolymers are considerably more planar and are shown to form partially ordered domains.

引用

页码：1346 / 1356

页数：11

共 55 条

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