The effect of reduced graphene oxide sheet on the optical and electrical characteristics of Ni-doped and Ag-doped ZnO ETLs in planar perovskite solar cells

Perovskite solar cells (PSCs) based on ZnO have strikingly succeeded recently and researchers are attempting to develop the next generation of affordable and high-power conversion efficiency (PCE (%)) of PSC based on ZnO. The aim of this study is to investigate the effect of reduced graphene oxide (rGO) sheet on the PCE (%) enhancement of nickel (Ni)-doped ZnO and silver (Ag)-doped ZnO at 5 wt% as electron-transport layers (ETLs) in planar PSCs. According to results, with a comparison between Ni-doped ZnO and Ag-doped ZnO ETLs, it is obtained that Ag doping at 5 wt% is helpful in charge carrier separation and, consequently, a reduction in the recombination rate by creating defect states for ZnO-based PSCs is obtained. According to J?V characteristics, the electrochemical impedance (EIS) and Mott-Schottky (MS), using rGO sheet interlayer significantly impacts the electrical properties in un-doped and-doped ZnO-based PSCs. According to the results, the rGO sheet can passivate un-doped ZnO and doped-ZnO ETLs as well as can assist in quickly charge-carrier extraction from the perovskite layer and decrease the recombination in PSCs. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study found that the use of 5 wt% Ag doping is beneficial for enhancing the performance of ZnO-based PSCs by reducing the recombination rate. By employing rGO sheets, significant improvements in the electrical properties of both undoped and doped ZnO ETLs were observed, leading to enhanced performance of PSCs.