Perovskite solar cells (PSCs) based on hybrid perovskite light absorbers have attracted much attention due to their superb power conversion efficiency (PCE). Perovskite absorb wide range of light from 400 nm to 800 nm. Lead halide which is a precursor material of highly efficient perovskite solar cells and absorb light from 380 nm to 550 nm. Individually Lead halide is used as a high-energy photon detector for gamma-rays and X-rays, due to their wide band gap. But Lead halide can be used as an active semiconducting materials for semitransparent solar cell with suitable structure.
In this study, spin coated mixed Lead halide films was investigated to reveal the effects of the experimental variables such as Lead halide composition, post annealing temperature with time and different solvent ratio on the growth and morphology of Lead halide films. Combination of Lead bromide with Lead iodide showed better surface coverage than only Lead iodide film on meso-TiO2 coated under layer. XRD, FE-SEM and UV-Visible spectroscopy was used to confirm the results. Lead bromide mixed Lead halide films showed improved film properties with promising application for device fabrication. Finally the device with the structure of FTO/c-TiO2/meso-TiO2/ Lead halide(s)/Spiro-OMeTAD/Au was fabricated. These device performance were characterized by using solar simulator and the stability was compared with perovskite solar cell.
Mixed Lead halide based solar cells shows promising results for the future application of semitransparent tandem structure to harvest larger range of sun lights.