Solution-processable thienoisoindigo-based molecular donors for organic solar cells with high open-circuit voltage
摘要:
Two acetylene-bridged Donor Acceptor Donor (D-A-D) type small pi-conjugated molecules involving triphenylamine or N-phenylcarbazole as donor blocks (D) and thienoisoindigo as the acceptor unit (A) were synthesized and characterized by UV-Vis absorption and cyclic voltammetry. These donor materials were mixed with [6,6]-phenyl-C-61-butyric acid methyl ester to prepare bulk heterojunction solar cells by simple solution processing. Due to their low-lying highest occupied molecular orbital energy levels, high open-circuit voltages up to 0.99 V were measured. The triphenylamine end-capped derivative led to the best power conversion efficiency of ca 2.20%, which ranks among the highest reported value for thienoisoindigo-based materials. (C) 2014 Elsevier Ltd. All rights reserved.