Influence of Ultraviolet Radiation on the Performance of Zinc Oxide Electron Transport Layer-Based Inverted Organic Photovoltaic Devices

Inverted organic photovoltaics (OPVs) have gained attention due to their environmental stability, lightweight structure, and cost-effectiveness in energy harvesting applications. However, the photostability of these devices is challenged by the light-soaking (LS) effect, especially when ZnO is used as the electron transport layer (ETL). This study investigates the impact of LS on the efficiency and photostability of ZnO-based inverted OPVs, specifically examining how exposure to sunlight with and without UV irradiation affects device performance. The results reveal that UV exposure during LS induces oxygen vacancies in ZnO, leading to a higher density of deep traps and reduced charge transport, which degrades the device efficiency over time. These findings suggest that minimizing UV exposure during LS can significantly improve the photostability of ZnO-based ETLs in OPVs, offering insights into enhancing the long-term reliability and efficiency of OPV devices for sustainable energy applications.