The influence of electrode buffer layers on the performance of polymer photovoltaic devices

The influence of electrode buffer layers (EBLs) on the performance of polymer photovoltaic (PV) devices based on blends of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-buytyric acid methyl ester (PCBM) has been investigated. Copper phthalocyanine (CuPc), bathocuproine (BCP) and pentacene are used as EBLs of solar cells to improve the photovoltaic performances, including short circuit current density (Jsc), open circuit voltage (Voc), power conversion efficiency (PCE) and fill factor (FF). The obtained results suggest that the insertion of EBLs can greatly improve the Jsc and PCE of the PV devices. And the effect of thickness of the four EBLs has also been explored and compared. The PV device with 1 nm BCP cathode buffer layer gets the highest PCE, which is 2.6 times that of the PV device without EBL.