Stabilization Procedures for TOPCon Modules after UV-Induced Degradation

The study investigates the stabilization behavior of Tunnel Oxide Passivated Contact (TOPCon) photovoltaic (PV) cell technology following UV-induced degradation (UVID). It focuses on the after-effects of lab-induced UVID, particularly the drastic effects of power loss during dark storage after UV irradiation. To counteract these effects, which are considered as artifacts that do not affect the expected outdoor performance, the paper presents light soaking at 25 °C module temperature as reproducible stabilization procedure for module performance measurements. Considering the increasing market presence of TOPCon-based PV modules and recent reports of, in some cases tremendous extent, UVID in the lab, stabilization after UVID is highly relevant. The study further explores the development of degradation during dark storage over time, different conditions for light soaking, as well as the potential of other approaches: While the repeated flashing is in principle applicable for post UVID-stabilization, current injection procedures showed negligible effect. Interestingly, high-temperature treatment reduces the degradation during dark storage. In that, the study offers insights that may inspire cell-level investigations of degradation and stabilization and improve understanding of underlying mechanisms.