Communication—large electron-hole diffusion lengths in methylammonium lead triiodide perovskite films prepared by an electrochemical-chemical approach

Abstract

Methylammonium lead triiodide (CH3NH3PbI3) perovskite films were generated by chemical conversion of PbO2 layers electrodeposited over NiO hole selective contact, by simple immersion in CH3NH3I isopropanol solution under ambient conditions. 2.4 μm charge carrier diffusion lengths were measured by surface photovoltage, being these very similar to the size of the as formed perovskite crystals, showing that there are not deleterious encounters with defects or impurities. The electrochemical procedure used here demonstrates the capacity of this technique for the fabrication of perovskite films with large electron-hole diffusion lengths by solution based processes using only water and isopropanol.