Study and fabrication of perovskite solar cells using TiO2/SnO2, TiO2/WO3 and SnO2/WO3 bilayer structures deposited by RF sputtering method as the alternative electron transport layers: a comparison between all bilayer types
Paper ID : 1275-ICNS
Mozhgan Kazemzadeh otoufi *
Department of Physics, Isfahan University of Technology, Isfahan, Iran
In planar perovskite solar cells, it is vital to engineer the extraction and recombination of electron–hole pairs at the electron transport layer/perovskite interface for obtaining high performance. The main idea here is to develop novel bilayer structures with different Fermi energy levels by combing a compact layer (CL) of 50 nm thickness as the major electron transport layer with an ultra-thin layer (UTL) of less than 10 nm thickness. We report applying all possible bilayer structured ETL types from TiO2, SnO2 and WO3, in order to investigate the role of energy band alignment in improving the efficiency. The structural and electrical characteristics of the samples were tested by XRD pattern, FE-SEM images, Mott-Schottky analysis, J-V characterization and UV-vis spectroscopy. Interestingly, current-voltage characterization results represent a significant efficiency improvement for the TiO2 CL/SnO2 UTL, TiO2 CL/WO3 UTL and SnO2 CL/WO3 UTL electron transport bilayer structures while it reveals worse performance for the cells based on the reverse structures, as well as expected. These achievements can be completely explained by more effective band alignment. The results of our work suggest a promising and simple approach to further design efficient photovoltaic devices from the aspect of charge transport and recombination.
Planar perovskite solar cell; RF sputtering; Electron transport bilayer; Interface engineering; Efficiency enhancement
Status : Abstract Accepted (Poster Presentation)