Perovskite Thin Film Preparation and Energy Band-Gap Determination for Solar Cell Applicatiosn

Abstract

Using Perovskite is a promising approach for upgrading the performance of an established low-bandgap Si photo voltaic (PV) solar technology because Perovskite is a high bandgap polycrystalline semiconductor compared with bulk Si and other semiconductors such as GaAs. In this work, Perovskite-structured methyl ammonium lead triiodide CH3NH3PbI3 uniform one-step planar thin films nanoparticles (NPs) have been developed from the reaction process of methylammonium iodide with PbI2 and deposited on a glass substrate by Aerosol Assisted Chemical Vapor Deposition (AACVD) to minimize the size of the solar cell and to reduce the cost and increase efficiency. This aims at the study and investigation of the energy bandgap (Eg) of nano-architectured solar cells absorber film as light harvesters. The X-ray diffraction (XRD) patterns of a CH3NH3PbI3 film on glass substrates are recorded by X' Pert Ultima IV X-ray diffractometer. Optical band gap of CH3NH3PbI3 is estimated by UV−Vis absorption spectroscopy and extracted from the absorption spectrum of the Tauc plot to be 1.63 eV. The Perovskite deposited on glass appears efficient to absorb most of the light with wavelength below 800 nm with a refractive index (n): 2.75. The film thickness was measured by an optical profile-meter to be about 200 nm, giving small reflectivity of 0.23 and resulting in efficiency enhancement of 15.7 %.