Comparative study of the optical and structure characteristics of CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf>: DMSO perovskite films with and without chlorobenzene

Abstract

Perovskite solar cell (CH3NH3PbI3) films were prepared with spin coating technique using different molarity concentrations of CH3NH3I and PbI2 in dimethyl sulfoxide (DMSO) solution as a solvent. Another set of films was formed with the same molarity concentrations, but chlorobenzene (CB) was dropped on the film surface as an anti-solvent at the last step of the spin coating. The phases formed, lattice parameters, crystallite size, and dislocation density were determined by applying Rietveld method for analyzing X-ray diffraction patterns measured for the samples. Field Emission Scanning Electron Microscope revealed that the number of pinholes were affected by the molarity concentrations of CH3NH3I and CB. The effects of molarity concentrations of the perovskite precursors solution, and using the anti-solvent on the transmission, reflection and absorption spectra and the direct optical band gaps were studied in detail. The dielectric constant, dissipation factor, and the optical conductivity of the films prepared with CB were observed to be higher than the corresponding films prepared without CB. The influence of molarity concentrations of MAPbI3 and the presence of CB on the photoluminescence (PL) peaks positions and their intensities was explored using PL technique with the laser source 532 nm.