Solution processable donor materials based on thiophene and triphenylamine for bulk heterojunction solar cells

Abstract

Solution processable and thermally stable donor materials 2,5-bis[4-(N,N-diphenylamino)styryl] thiophene (1) and 2,5-bis[4-(N,N-diphenylamino)styryl]-2,2′-bithiophene (2) were synthesized for bulk heterojunction solar cells, which consist of a thiophene, or bithiophene and triphenylamine unit linked with conjugated bonds. The best device performance, optimized at 1 : PCBM = 1 : 3 and 2 : PCBM = 1 : 4, exhibited the maximum open circuit voltages of 0.56 and 0.51 V, short circuit currents of 1.33 and 1.88 mA cm−2, and power conversion efficiencies of 0.23 and 0.34%, respectively, under simulated AM 1.5 solar irradiation at 100 mW cm−2.