Study of Potential-Induced Degradation in Glass-Encapsulated Perovskite Solar Cells under Different Stress Conditions

Potential-induced degradation (PID) is an important reliability issue of photovoltaic modules. For future field applications of perovskite photovoltaic modules, it is important to study the PID behavior under real-world operating conditions, which has not yet been thoroughly researched. This work presents PID investigation of glass-encapsulated perovskite solar cells (PSCs) at different stress conditions for an extended duration of 55 h. At room condition (25 degrees C, 20% relative humidity [RH]) the efficiency is reduced by 59% when -1000 V is applied to the short-circuited PSCs, whereas under elevated stress condition (60 degrees C, 60% RH) the device efficiency suffers severe degradation of >90%. The PID effects are analyzed with several characterization methods, revealing that Na+ ion migration from the front glass pane toward the perovskite layer causes the degradation. Application of a reverse voltage bias right after PID results in very poor recovery under elevated condition compared to the recovery of devices under room condition. It is proposed that PID and its recovery rate depend on the external stress conditions and the reverse bias strategy is not sufficient for the recovery. Possible mitigation strategies which can open a new avenue for further research on PID in PSCs are also presented.