High performance ZnO cathode interface doped by organic electrolyte and inorganic metal ion for organic solar cells

In this work, we study the modification effect on the performance of organic solar cells (OSCs) by introducing the ZnO dual doped by Al(NO3)(3):PEIE cathod interlayer. The results showed that, with a proper doping concentration, the Al(NO3)(3) doped ZnO (ZnO:Al), PEIE doped ZnO (ZnO:PEIE) and Al(NO3)(3):PEIE dual doped ZnO (ZnO:Al:PEIE) cathode interlayers all exhibited the superiority for their application on inverted organic solar cells (iOSCs), due to their reduced work function (WF), better properties of electron transport, smoother interface contact between the electrode and active layer, thus leading to improvement of device performance. Based on PTB7-Th:PC71BM, the power conversion efficiency (PCE) got dramatically increased to 9.51% with PEIE:Al dual doped ZnO, compared to the reference PCE of 8.27% with pure ZnO.