Ternary organic solar cells: Improved optical and morphological properties allow an enhanced efficiency

The power conversion efficiency (PCE) of OFQx-T:PC71BM blend films reaches 7.59%. On this basis, ternary organic solar cells (OSCs) were fabricated with ITIC or PTB7-Th as the third component. The ternary OSCs with 50 wt% ITIC in acceptors exhibits an enhanced efficiency, from 7.59% to 8.17%. Also, the PCE of ternary OSCs with 50 wt% PTB7-Th in donors achieves 8.72%, which is 13% higher than that of binary OSCs. The PCE improvement of two ternary OSCs is mainly due to the increase of short-circuit current density (Jsc), which can be attributed to the complementary absorption spectra and improved film morphology. This work suggests that the selection of an appropriate third component plays a critical role in improving the PCE of ternary OSCs.