Proceedings of Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP20)
Publication date: 14th October 2019
Evaporation method has been studied for forming a perovskite layer on the any substrates directly without any solvents [1]. In this presentation, the perovskite layer was prepared by a co-evaporation method of lead iodide (Ⅱ) and methylamine hydroiodide (MAI) or formamidine hydroiodide (FAI). Evaporation conditions were examined as the evaporation rate of MAI and FAI of 0.1 nm/s and the pressure of <1.0×10-3 Pa for forming dense perovskite layers. The co-evaporation method with optimized conditions gave the homogeneous perovskite layer of ca. 100 nm thickness, which also showed small residual PbI2.
Formamidine hydrobromide (FABr), which has been applied as a surface passivation for filling defects of the perovskite surfaces to enhance the quality of the perovskite layer [2], was deposited on the perovskite layer by the evaporation method for enlarging the cell area. Photovoltaic conversion performance, especially a fill factor, of the cells was improved by the evaporated FABr surface passivation.
The hole-transporting polymer was also applied as an effective hole-transporting layer on the evaporated homogeneous and flat perovskite layer.
This work was partially supported by NEDO project, Japan.