Improving power conversion efficiency by Light-Assisted annealing of triple cation perovskite layer in solar cell applications

Abstract

Here we propose a light-assisted annealing (LA) method, for the formation of relatively larger and uniform grains of triple perovskite crystals with less nano-cracks in a custom designed LA system with a 250 mW/cm2 halogen lamb. This method has the potential to reduce the annealing process time and energy consumption for mass production of perovskite solar cells (PSCs). For this purpose, initially, a series of perovskite films are prepared by LA method with various annealing time (1, 3, 5, 10, 15 min) to determine the optimum conditions. Subsequently, a comparative study is carried out for morphology, crystal structure and optic characterization. To assess the effect of the LA process on the structure and morphology of perovskite crystals, X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and UV–Vis absorption spectroscopy techniques are carried out. Consequently, the photovoltaic application and stability tests are carried out with LA and TA films. A power conversion efficiency (PCE) of 17.86 % is achieved with an LA device annealed for 5 min (5-min-LA), while that of 16.74% is obtained with the standard device annealed on a hotplate for 60 min (60-min-TA).