Enhanced efficiency of ternary organic solar cells by doping a polymer material in P3HT:PC61BM

摘要

Doping a low-bandgap polymer material (PDTBDT-DTNT) as a complementary electron donor in poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C-61-butyricacid methyl ester (PC61BM) blend is experimented to improve the power conversion efficiency (PCE) of organic solar cells (OSCs). The PCE of OSCs was increased from 3.19% to 3.75% by doping 10wt% PDTBDT-DTNT, which was 17.55% higher than that of the OSCs based on binary blend of P3HT:PC61BM (host cells). The short-circuit current density (J(sc)) was increased to 10.11mAcm(-2) compared with the host cells. Although the PCE improvement could partly be attributed to more photon harvest for complementary absorption of 2 donors by doping appropriate PDTBDT-DTNT, the promotion of charge separation and transport as well as the suppression of charge recombination due to a matrix of cascade energy levels is also important. And the better morphology of the active layer films is beneficial to the optimized performance of ternary devices.