Proceedings of MATSUS23 & Sustainable Technology Forum València (STECH23) (MATSUS23)
Publication date: 22nd December 2022
The development of environmentally benign metal halide perovskite materials became an urgent issue as solar cells based on Pb-containing hybrid organic-inorganic perovskites reached the power conversion efficiency comparable to conventional inorganic semiconductors, thus facing the full-scale commercialization. The search of less toxic metals to replace Pb brought researchers to Sn, resulting in reports on tin-halide perovskites as CH3NH3SnI3 (MASnI3) or HC(NH2)2SnI3 (FASnI3) promising candidates for sustainable photovoltaics of tomorrow [1,2]. Nevertheless, the easy oxidation of Sn(II) to Sn(IV) became a shortcoming significantly affecting the performance of devices. The promising opportunity to overcome this obstacle appeared with layered perovskites, in which large organic cations are inserted between 3D inorganic layers forming materials with improved temperature and humidity stabilities [3].
In this work we investigate a new, in-house synthesized 2D tin halide perovskite deposited on GaN substrate. By means of contactless electroreflectance spectroscopy we probed the perovskite/GaN interface in order to assess the charge carrier transfer across it. Thanks to adopted methodology involving unique GaN substrates architecture we were able to non – invasively probe the influence of perovskite on GaN surface states. This brought us to conclusions allowing to trace the relative band alignment of investigated 2D Pb-free perovskite comparing to GaN.
This work was supported by the National Science Centre (NCN) in Poland through PRELUDIUM grant no. 2022/45/N/ST3/03465 and through OPUS grant no. 2019/33/B/ST3/03021.