Effect of Perovskite CsPbBr<sub>3</sub> Concentration and Coating Method on Thin Film Morphology and its Photovoltaic Performance

Perovskite CsPbBr 3 has a band gap energy of 2.3 eV which has the potential for solar cell applications. The issue regarding the relationship between the different coating methods and the concentration has not been studied further. Therefore, this study focuses on analyzing the effect of variations in the concentration of CsPbBr 3 20 mM and 40 mM as well as d ifferent coating methods, spin-coating, dip-coating and drop-c asting on the morphology of the thin film. The ligand assisted reprecipitation LARP method was used to synthesize CsPbBr 3 using control ligands, octylamine and oleic acid to obtain CsPbBr 3 orthorhombic . Scanning Electron Microscopy (SEM) observations show that increasing the concentration resulted in larger particle size, and the Drop Casting method resulted in a more ful l y coverage on thin film. Drop Casting and a 40 mM solution produced the highest solar cell efficiency of 1.4 %.