A New Low-Bandgap Polymer Containing Benzene-Fused Quinoxaline: Significantly Enhanced Performance Caused by One Additional Benzene Ring

• Published in: Macromolecular rapid communications. Vol. 34; no. 3; pp. 227 - 233
• Main Authors: Li, Shuang, Li, Aiyuan, Yu, Jian, Zhong, Aoshu, Chen, Su'an, Tang, Runli, Deng, Xianyu, Qin, Jingui, Li, Qianqian, Li, Zhen
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 12.02.2013; WILEY‐VCH Verlag; Wiley; Wiley Subscription Services, Inc
• Subjects: Addition polymerization; Applied sciences; Benzene; Benzene - chemistry; benzene-fused quinoxaline; Copolymers; Energy; Exact sciences and technology; low-bandgap; Molecular Structure; Natural energy; Organic polymers; Photovoltaic cells; Photovoltaic conversion; Physicochemistry of polymers; polymer solar cells; Polymers; Polymers - chemical synthesis; Polymers - chemistry; Polymers with particular properties; Preparation, kinetics, thermodynamics, mechanism and catalysts; Quinoxalines; Quinoxalines - chemistry; Rings (mathematics); Solar cells; Solar cells. Photoelectrochemical cells; Solar energy; Terpolymer; Stille coupling; Short circuit currents; Electrical properties; Solution polycondensation; Quinoxaline derivative copolymer; Hole mobility; Thiophene copolymer; benzene-fused quinoxaline; polymer solar cells; Organic solar cells; Fill factor; Thermal stability; Open circuit voltage; Phenazine derivatives; Electrochemical properties; Conjugated copolymer; low-bandgap; Optical properties; Preparation; Aromatic copolymer; Thiophene derivative copolymer; Optical absorption
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.201200623

Two new alkoxy‐substituted quinoxaline (Qx)‐based copolymers, PBDTQx and PBDTPz, are designed and synthesized. The only difference between these two polymers is that two methyl groups of the Qx are replaced by one additional fused benzene ring. The UV–Vis absorptions, thermal stability, energy levels, field‐effect carrier mobility, and photovoltaic characteristics of the two copolymers are systematically evaluated to understand the relationships between the polymer structure at the molecular level and the photovoltaic performances. Photovoltaic cells based on the PBDTPz with a structure of ITO/PEDOT:PSS/Polymer:PC71BM/PEO/Ca/Al exhibit a promising efficiency of 4.40%, while that of PBDTQx is relatively much poorer. Two new alkoxy‐substituted quinoxaline (Qx)‐based copolymers, PBDTQx and PBDTPz, are designed and synthesized. The only difference between the two polymers is that two methyl groups of quinoxaline are replaced by one fused benzene ring leading to totally different power conversion efficiencies..