Insights into the replacement of FA by Cs in FAPbI3−xClx thin film fabricated in atmospheric conditions: Inspection of solar cell and photocatalytic performances

Abstract

Despite remarkable advances of perovskite materials, the stability issue hurdles in the path of commercial deployment of perovskite solar cell and optoelectronics devices. To overcome these, CH3(NH)2PbI3−xClx thin film is deposited by chemical spray pyrolysis (CSP) technique at a temperature of 125 °C under atmospheric conditions and then CH3(NH)2 free Cs based in the form of CsPbI3−xClx is synthesized. The precursor solution shows turbid in nature which became transparent slowly, and after 60 min stirring it became highly transparent that insights crystallization formation for the thin film growth. SEM images exhibit the thin films are pinholes free with grains size (Ave. ∼2 µm) of FAPbI3−xClx are larger enough than that of CsPbI3−xClx. The high crystalline property with pinhole-free surfaces are prerequisite for high performance optoelectronic devices applications. Coexistence mixed phases are observed in XRD patterns could be due to decomposition and/or incomplete reaction of the phases. The thin films exhibit cubic and orthorhombic crystal structures. Grains size and lattice parameters calculations are demonstrated that the films are micro-nanostructures, and their size strongly depends on the films constituents. Band gap can be tuned in between 1.70. eV and 1.62 eV. The solar cell performance was investigated using SCAPS-1D software and the obtained efficiency is to be η = 12.29% of FAPbI3−xClx is coherent with reported results, whereas of CsPbI3−xClx is to be η = 11.15%. From the theoretical photocatalytic calculation, it can be concluded that FAPbI3−xClx may be suitable for O2 production, but CsPbI3−xClx is an efficient candidate for photocatalytic process in the visible region due to nearly equal effectiveness both of the oxidation and reduction processes. Thus, CsPbI3−xClx as a new candidate perovskite for solar cell and photocatalytic applications, requires further attention.