Improved stability of ambient air-processed methylammonium lead iodide using carbon nanotubes for perovskite solar cells

Abstract Methylammonium lead iodide (MAPI3) material is promising for use in photovoltaic (PV) cells because of its efficient optoelectrical properties. However, the ambient air processed MAPI3 layer is unstable to ZnO film mainly during the annealing process. Herein, XRD results showed that the MAPI3 layer on the top of the ZnO photoelectrode is converted into lead iodide (PbI2) because of the existence of hydroxide agents on the surface of the ZnO layer. For this reason, the MAPI3 based PSCs showed poor power conversion efficiency (PCE) of 9.95 % with a hysteresis effect. In order to tackle this problem, we report here on a carbon nanotube (CNT)-incorporated MAPI3 perovskite film made in ambient air and is employed as an effective absorber layer. Our results demonstrate that optimized PSC based on CNT additive shows a PCE up to 15 %.