ИСТИНА

Perovskite solar cells represent a highly promising 3rd generation photovoltaic technology. However, its practical implementation is hindered by a low device operational stability mostly related to facile degradation of the absorber materials under exposure to light and elevated temperatures. Improving the stability of complex lead halides is a big challenge, which might be addressed using various “molecular modifiers”. These modifiers usually undergo strong interactions with the perovskite absorber material resulting in enhancement of solar cell efficiency and/or operational stability. Herein, we present a derivative of 1,4,6,10-tetraazaadamantane NAdCl as a promising molecular modifier for lead halide perovskites. NAdCl spectacularly improved both thermal and photochemical stability of APbI3 (A univalent cation(s)) films and, most importantly, prevented the formation of metallic lead Pb0 as a photolysis product. It was shown that NAdCl improves the electronic quality of perovskite films by healing the traps for charge carriers. Furthermore, it strongly interacts with the perovskite framework and most likely stabilizes the undercoordinated Pb2+ ions, which are responsible for Pb0 formation under light exposure. The obtained results feature 1,4,6,10-tetraazaadamantane derivatives as highly promising molecular modifiers, which might help to improve the operational lifetime of perovskite solar cells and facilitate the practical implementation of this photovoltaic technology.