Low-Temperature Deposition of Perovskite CH3NH3PbX3 (X = I, Br) Thin Films Using Aerosol Assisted CVD via Vertical Flow for Photovoltaic Applications
Abstract
Research on organo-metal halide perovskite as a light harvester in solar cells has progressed rapidly. However, large-scale synthesis of these materials is an ongoing challenge. We demonstrate the deposition of methylamine lead iodide (CH3NH3PbI3, MAPI) and methylamine lead bromide (CH3NH3PbBr3, MAPBr) using atmospheric pressure aerosol-assisted chemical vapor deposition (AACVD) via vertical flow onto a glass substrate at a low temperature of 100 oC. The results show that a micron-scale perovskite thin film can be deposited within minutes at a lower temperature. The optical and structural properties of deposited thin films have been analyzed by various techniques, including powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, UV-Vis absorption spectroscopy, and photoluminescence (PL) spectroscopy. The diffraction pattern obtained from as-deposited films of MAPI shows a tetragonal structure, while MAPBr shows a cubic structure, confirming their crystallinity. The as-deposited films exhibit a sharp absorption offset at 800 nm for MAPI with an optical bandgap energy (Eg) of 1.56 eV and 550 nm for MAPBr, with an Eg of 2.27 eV.