Investigation of structural and optical properties of rGo alloyed CsSnBr3 for solar cell application

Abstract

The lead-free metal trihalide perovskite material has been extensively studied due to its promising, and outstanding optoelectronic properties. Herein, we have studied the impact of alloying on CsSnBr3 perovskite nanoparticles with reduced graphene oxide (rGO) on its structural and optical properties for its utility in solar cell devices. The formation of phase and highly crystalline behavior of the pristine CsSnBr3 and rGO alloyed CsSnBr3 has been observed by the X-ray diffraction (XRD) technique. A direct bandgap of 1.81 eV and 1.75 eV has been calculated from the Tauc plot for CsSnBr3 and rGO alloyed CsSnBr3 respectively indicating a decrease in band gap due to rGO alloying. The photoluminescence (PL) plot represents a blue shift phenomenon in the PL peak of CsSbBr3 after rGO alloying. Also, a decrease in full-width half maxima (FWHM) has been seen after alloying CsSnBr3 with rGO which further indicates an increase in crystalline size and a decrease in grain boundaries. Furthermore, the surface morphology of rGO alloyed CsSnBr3 has been noticed from scanning electron microscopy (SEM) images depicting a nano rod-like structure uniformly spread over the rGO sheet. This study suggests structural and optical tuning along with enhancement in properties of CsSnBr3 after rGO alloying for its utility in the fabrication of high-performance and ultra-stable solar cell devices.