OPTIMIZING THE DEPOSITION OF THIN LAYERS OF ORGANIC-INORGANIC HYBRID PEROVSKITE METHYLAMMONIUM LEAD IODIDE (CH3NH3PBI3) ON LARGE SURFACES THROUGH THEIR OPTICAL PROPERTIES

摘要

Nowadays, most of the Research and Development (R&D) efforts devoted to perovskite solar cells have been focused on achieving higher power conversion efficiencies, by using small sized substrates with even smaller active areas. The present paper proposes a method for optimizing the deposition of thin layers of organic-inorganic hybrid perovskite methylammonium lead iodide (CH_3NH_3PbI_3) on large surfaces (up to 75 mm × 75 mm) via spin coating procedures, performed in a clean room environment at room temperature and by considering their optical properties to assess their quality. Thus, in order to map the deposited area and realize studies about their optical properties, the absorption coefficient, the refractive index and layers thicknesses were determined by using a high accuracy spectroscopic ellipsometer system based on rotating compensator ellipsometer (RCE) technology from the J.A. Woolam Co. as functions of the wavelength, within a spectral range from 250 to 800 nm. Also, the samples were studied with a fluorescence spectroscopic system, in order to evaluate their photoluminescence properties and, in order to validate the chosen methodology; an Atomic Force Microscopy was used to verify the layers uniformity and thicknesses.