Natural material from carnauba wax to enhance the moisture stability for high-efficiency Perovskite solar cells

Organic-inorganic hybrid halide perovskites have great potential in solar cells, but they suffer from moisture-induced instability. In this study, we developed a natural material-- tetracosanoic acid (TA) to modify the surface of CH₃NH₃PbI₃ perovskite films to enhance the moisture stability. The power conversion efficiency (PCE) of the TA modified perovskite solar cells (PSCs) retained ~85% of their initial PCE when stored for 20 days at a relative humidity of 25% at 25°C, whereas a pristine cell only retained 54% of its initial value. Our findings demonstrated a simple, inexpensive, and environmentally friendly method to improve moisture stability of PSCs.