A Study of Hysteresis and Resistance Evolution in Perovskite Mini-Modules Exposed Outdoors

Abstract Hysteresis effects and series/shunt resistances in perovskite devices have previously been reported to provide signatures of ion dynamics, transport, and leakage losses that continuously change over time and during outdoor day/night cycles. This work studies the temporal evolution of hysteresis effects, series, and shunt resistances, as well as the correlations between these parameters and environmental and performance variables for different perovskite mini-module architectures. This analysis is based on data from 1 year of field testing of perovskite mini-modules, as well as indoor light cycling tests performed at different temperature levels. The latter tests aim to shed light on the evolution of hysteresis and resistance effects and support the outdoor results. Hysteresis is found to show a weak correlation with performance-related parameters in the perovskite structures under test. This demonstrates that hysteresis cannot be considered a standalone figure of merit for assessing the degradation of perovskite-based devices. An increase in series resistance was found to be one of the most significant degradation mechanisms in the mini-modules under test, while being strongly correlated with irradiance and temperature. A statistical analysis reveals that hysteresis changes throughout the day, with lower values observed in the afternoon. Indoor light cycling experiments show more pronounced variations in hysteresis and series/shunt resistances at high temperatures, with consistent recovery observed during the dark cycles.