Title: Device design optimization of highly efficient perovskite solar cell

Abstract

In order to provide experimental guidance, a theoretical study was performed on transparent conduction oxide (FTO)/TiO2/interface defect layer 1/CH3NH3SnI3/interface defect layer 2/Cu2O/ back contact solar cell. The simulation was performed under the illumination of 1000 W/m2, at 300 K and an air mass of AM 1.5G. The diffusion lengths of electron and hole were set to 260 nm and 560 nm in absorber layer, respectively. The set value is very near to recently observed experimental values. The device performance is severely influenced by the thickness of absorber layer, acceptor density, defect density and work function of various back contact electrode materials. Oxidation of Sn2+ into Sn4+ was considered and it is found that the reduction of acceptor concentration of absorber layer significantly improves the device performance. Further, optimizing the defect density (1014 cm−3) of the perovskite absorber layer, encouraging results of the Jsc of 40.14 mA/cm2, Voc of 0.93 V, FF of 75.78% and PCE of 28.39% were achieved. This theoretical simulation provides an appropriate direction for devolving photovoltaic technology.