Low temperature processing of flexible planar perovskite solar cells with efficiency over 10

A device fabrication method is reported to efficiently produce CH sub(3)NH sub(3)Pbl sub(3 )-based planar perovskite solar cells on polymer substrates with the entire process conducted at 150 C or below. The hole blocking layer employed is a solution processed 100 nm thick mesoporous TiO sub(2) layer. A gas-assisted perovskite deposition method is used to produce excellent coverage of the hole blocking layer by a -350 nm thick CH sub(3)NH sub(3)Pbl sub(3 ) film, resulting in high device performance reproducibility. We show that an average efficiency of 10.6 + or - 1.2%, and a maximum efficiency of 12.3% are obtained for flexible perovskite solar cells, offering great promise for further improvement of this low-temperature, low-cost processing solar technology.