A comparative study on the band diagrams and efficiencies of silicon and perovskite solar cells using wxAMPS and AMPS-1D

wxAMPS is a popular software widely used in simulating state-of-art solar cells; however, the official documentation for it does not exist. Herein, we compiled information from literature and compared the wxAMPS simulation results with the software it was developed from, AMPS-1D. We first delineated three new tunneling models introduced in wxAMPS: trap-assisted, intra-band, and band-to-band, and highlighted its salient features of the GUI, file I/O, data visualization, and numerical methods. Conventional c-Si solar cells were then used to elucidate the origin of the photovoltaic response. It was evident that devices operating on the built-in electrostatic field achieved a higher efficiency (3%) than those on the effective field (0.05%) and Dember effect (almost zero). High-efficiency Si solar cells in p-n and p-i-n junctions were further studied. It was found both hole and electron transport layers play critical roles in optimizing the power conversion efficiencies. An occasional convergence issue was observed in calculating charge carrier densities in p-i-n device, in which case the slightly deviated JV characteristics can be mainly attributed to the tunneling models. When running the batch simulation on homojunction perovskite solar cells, the voltage bias step size was tuned smaller than 0.01 V in wxAMPS to produce data of higher accuracy than AMPS-1D. Among all the performance parameters, the fill factor was found to be most sensitive to the voltage bias step.