Abstract
The article describes a number of new fundamental knowledge about mechanisms of degradation processes occurring in photoactive perovskite materials based on complex lead halides and solar cells based on them, modern methods and approaches to increasing the operational stability of perovskite photovoltaic devices are considered. The revealed paths of degradation processes occurring in complex metal halides (lead and tin) under the influence of light and elevated temperatures are important for further developments in the field of creating highly efficient and stable perovskite solar cells of a new generation. The investigated models of degradation are described both under the action of moisture and as a result of radiation ionization processes. The importance of solving the Dexter-Varley paradox, which takes into account the competition between the processes of displacement of IS0 states, as well as the delocalization of the resulting hole in the valence band, is emphasized. It was shown that by changing the force of pressure of the tape on the perovskite film, it was possible to achieve the maximum values of the light conversion efficiency of about 12.7%. It was found that the presence of charge carriers in the form of polarons can significantly affect the assessment of the degradation efficiency towards its increase. The data obtained can radically change the traditional ideas about the efficiency of photochemical reactions.