Highly reproducible perovskite solar cells with excellent CH3NH3PbI3−xClx film morphology fabricated via high precursor concentration

Abstract

To meet the large-scale fabrication technology of perovskite solar cells in the future, a novel method is proposed herein to achieve an excellent and highly reproducible CH₃NH₃PbI_3−xCl_x film based on a high concentration spinning process. Pinholes in the CH₃NH₃PbI_3−xCl_x film were substantially reduced, leading to better uniformity and film coverage. The precursor ions and molecules promoted nucleation and growth while releasing by-products gradually, which was beneficial to continuous growth and crystallization of the perovskite film in high concentration conditions and then resulted in significantly enhanced optoelectronic characteristics and device performance. Up to 13.8% of power conversion efficiency had been achieved by employing the FTO/bl-TiO₂/mp-TiO₂/CH₃NH₃PbI_3−xCl_x/Spiro-MeOTAD/Au device structure under AM1.5 global spectral irradiation (100 mW cm⁻²). This method offered an efficacious and simple strategy for a highly reproducible large-area fabrication process of low-cost perovskite solar cells.