Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV19)
Publication date: 6th February 2020
Deposition method of organo-metal halide perovskite films for solar cells is classified into two: one is solution method, and another is vapor phase method. Among the vapor phase methods, dual source vacuum evaporation is a promising deposition method for perovskite films. High-efficient perovskite solar cells using this method have been reported [1,2]. However, it is difficult to control the vapor pressure of methylammonium iodide (MAI) during the deposition. Here, we present for the first time a novel vapor deposition method for MAPbI3 films using the hot-wall method to control vapor pressure of MAI. This novel deposition method was designed to convert two source materials (MAI and PbI2) into MAPbI3 perovskite phase suppressing the spreading of MAI gas in a vacuum chamber. Using this method, we have successfully deposited MAPbI3 films at low substrate temperature of 40°C. The structural characterization and surface morphology of the deposited films were examined by X-ray diffraction and AFM observation, respectively. We also fabricated inverted planar heterojunction solar cells with a glass/TCO/HTL/MAPbI3/C60/BCP/Ag structure using the deposited MAPbI3 films. In the solar cells, we used PEDOT:PSS and copper phthalocyanine (CuPc) as hole transport layer (HTL). The best solar cell exhibited a power conversion efficiency of 11.6% for forward scan and 12.8 % for reverse scan.
This study was financially supported by the Iwatani Naoji Foundation.