Yuichi Haruyama

Abstract The impact of NiOx layers on the performance of inverted perovskite solar cells (PSCs) has been investigated using multiple analysis methods (thermal gravimetric, differential thermal analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and Soft X-ray photoelectron spectroscopy) of NiOx layers, which were made by spray pyrolysis deposition at different temperatures. The analyses of this study indicate that the efficiency of inverted PSC increases with the Scherrer crystallite size of NiOx. We also observed that the band state of the NiOx layer was changed by Na+ ions migrated from the glass substrate, which also had an impact on the efficiency. The results clearly showed that under high fabrication temperature, migration of matter from the substrate to the hole transport layer affects the electronic structure. Therefore, how these materials are engineered will be important to increase the efficiency of inverted PSCs.