A study of the performance of organometal trihalide perovskite solar cell due to defects in bulk CH3NH3PbI3 (MAPI) perovskite layer

In this numerical simulation research, we have investigated device performances of p-i-n type organometal trihalide perovskite solar cell by introducing deep and shallow defects in the bulk halide perovskite layer. The organometal halide perovskite solar cell device structure has Glass/ITO/PEDOT:PSS/Bulk-MAPI/2D-MAPI/PCBM/Ag. The open-circuit voltage of the solar cell was decreased due to both shallow and deep defects of the bulk-MAPI layer which increase the recombination of electron-hole pairs in the solar cell. The dark saturation current, which causes to reduce the open-circuit voltage of the solar cell, was increased due to the deep defects in the bulk-MAPI layer. Therefore, the power conversion efficiency of the solar cell can be enhanced by minimizing the deep defects in the bulk-MAPI layer, which can increase the open-circuit voltage of the solar cell by suppressing the effect of dark saturation current. We have verified that Shockley-Read-Hall (SRH) recombination is the most predominant recombination mechanism when only the deep defects are presented in the bulk-MAPI layer. Also, this investigation has proved, that Radiative recombination has become the most predominant recombination mechanism when the shallow defects are presented in the bulk-MAPI layer by completely omitting the deep defects of the bulk-MAPI layer. Finally, our model verified that the dark saturation current of the solar cell controls the open-circuit voltage when the recombination is occurring in the solar cell. Iodine interstitial defects that mainly act as deep defects in the bulk-MAPI layer should be minimized to increase the overall solar cell performance and power conversion efficiency of the organometal trihalide perovskite solar cell device. KEYWORDS: Perovskite-Based Solar Cell, Recombination, Dark Saturation Current, Defects, Power-Conversion Efficiency