Chlorine Incorporation in Perovskite Solar Cells for Indoor Light Applications

Summary Development of efficient solar cells under indoor light has attracted tremendous attention because of the Internet of Things revolution. Here we investigate the effect of chlorine in perovskite precursors for indoor light applications. Use of chlorine has an effect on the photovoltaic performance of perovskite solar cells, especially under low-intensity indoor light. Based on the characterization of leakage current, crystalline structure, and Urbach tail, we reveal that chlorine doping of the perovskite layer influences the movement of photo-generated carriers and ions because of the smaller bulk defects in perovskite. In particular, we suggest that chlorine doping in perovskite facilitates hole extraction on its top surface and contributes to suppression of ion migration and non-radiative recombination, as confirmed by Kelvin probe force microscopy measurements. We demonstrate high performance of perovskite solar cells with a maximum power density of 35.25 (231.78) μW/cm2 under 400 lux light-emitting diode (halogen) illumination.