Synergistic effect of CdSe quantum dots (QDs) and PC61BM on ambient-air processed ZnO QDs/PCDTBT: PC61BM:CdSe QDs/MoO3based ternary organic solar cells

Abstract

This paper reports the synergistic effect of colloidal CdSe quantum dots (QDs) and PC61BM on the performance of ITO/ZnO QDs/PCDTBT:PC61BM:CdSe QDs/MoO3/Ag based ternary organic solar cells (OSCs). The MoO3 and ZnO QDs (∼2.87 nm) layers work as the transparent hole transport layer (HTL) and electron transport layer (ETL), respectively. The CdSe QDs (∼4.58 nm) are blended with PC61BM:PCDTBT binary solution to improve the optical properties and charge transportation. Significant photoluminescence (PL) quenching is observed when part of the PC61BM is replaced by CdSe QDs with equivalent weight in the PCDTBT. The proposed ternary OSC gives an open-circuit voltage of 854 mV, a short circuit current density of 14 mA cm-2, fill factor of 42% and power conversion efficiency (PCE) of 5.02%. The PCE of the ternary OSC is increased by more than 38% compared to the binary OSC. This significant improvement in the performance parameters is attributed to the enhanced absorption and higher transportation of photo-generated charge carriers, as well as the increased charge dissociation due to the synergistic effect of CdSe QDs and PC61BM. The external quantum efficiency is also enhanced significantly in the ternary OSC due to the better conversion of solar energy into electrical energy. © 2020 IOP Publishing Ltd.