A Solution‐Processed Organometal Halide Perovskite Hole Transport Layer for Highly Efficient Organic Light‐Emitting Diodes

A new type of hole transport layer (HTL) based on organometal halide perovskite for highly efficient organic light‐emitting diodes (OLEDs) is demonstrated. By solution processing of methylammonium lead chloride (CH3NH3PbCl3) precursors, smooth neat perovskite thin films can be prepared with high transparency and conductivity. A solution‐ processed multilayer OLED with this perovskite HTL outperforms a device with a PEDOT:PSS layer.