Title : Investigation of interfaces defects, recombination rate and work function of electrode in solar cell devices
In order to provide experimental guidance, a theoretical study was performed on transparent conduction oxide (FTO)/ZnO/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 results. 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. The role of oxidation of Sn-based perovskite and its effect on band offset was emphasized at Cu2O/CH3NH3SnI3 and CH3NH3SnI3/ZnO interfaces. The PCE has been enhanced to 23.23% by optimizing the defect density in absorber layer. Further, various back contact electrode such as Al, Ag, Cu, Au and Pt were investigated. Finally, the optimized photovoltaic parameters of intended solar cell are found to be a Jsc of 38.56 mA/cm2, Voc of 1.18 V, FF of 66.22% and PCE of 28.47%. This theoretical simulation provides an appropriate direction for devolving photovoltaic technology.