Binary hole transport materials blending to linearly tune HOMO level for high efficiency and stable perovskite solar cells

Binary hole transport materials blending to linearly tuning HOMO level for high efficiency and stable perovskite solar cells have been developed for the first time. Ideal HOMO level is acquired by optimizing the composition of binary HTLs. A maximum power conversion efficiency of 19.85% is achieved for cells with negligible hysteresis. The un-encapsulated devices maintain over 82% initial efficiency after 60 days' storage with ~ 50% relative humidity.240