Preparation of compact TiO2 thin film by artist spray gun-assisted pyrolysis method for lead-free perovskite solar cell

Abstract

In the present investigation, compact TiO2 thin film was prepared by using an artist spray gun (ASG)-assisted pyrolysis method to use as an electron transport layer (ETL) for perovskite solar cell (PSC). The influence of the distance between the spray gun nozzle and the substrate was studied to get quality TiO2 thin film onto FTO substrate among three different distantly deposited TiO2 thin films. The formation of anatase TiO2 thin film was confirmed by XRD and Raman spectroscopy studies. The bandgap of this thin film was measured by UV-Vis analysis and it was found to be 3.19 eV. The emission spectrum and charge separation of TiO2 thin film were analysed by photoluminescence studies. The emission spectrum of TiO2 thin film exhibited at 380 nm confirmed the indirect transition from the conduction band to the valence band. The FE-SEM image confirmed that the prepared TiO2 thin film was uniformly deposited over the substrate without any pinhole, which shows a good agreement with the Raman mapping analysis. A power conversion efficiency (PCE) of 2.69% has been achieved with Pb-free PSC fabricated from uniformly deposited TiO2 ETL.