Epoxy-based encapsulation of halide perovskite solar cells for outdoor stability assessment (ISOS-O)

A key factor in the widespread commercialization of perovskite solar cells (PSCs) is the need for comprehensive stability analysis, particularly under real-world outdoor conditions across diverse global locations. However, a simple and reliable encapsulation strategy for outdoor stability analysis that can be implemented at the laboratory level is currently missing, hindering progress in the study of PSC lifetime. In this work, we present a simple and effective two-step strategy to encapsulate laboratory-scale PSCs at room temperature, applying commercially available epoxies. We have examined nine epoxies, including single and bicomponent epoxies, as well as air-curing and UV-curing epoxies. The possible reaction of the epoxy’s fumes with the halide perovskite during epoxy curing was monitored by means of XRD analyses, SEM imaging, FTIR, and Raman spectroscopies, as well as via stability assessment of devices following ISOS protocols. The encapsulation method was analyzed in different types of PSCs, including normal n-i-p configuration applying Au and carbon electrodes, and inverted p-i-n configuration with Ag contacts. The devices, both in normal and inverted configurations, were also analyzed at different locations (Spain, Israel, and Germany), showing impressive stability under the ISOS-O protocol, demonstrating its viability for the analysis of lab-scale PSC devices. We hope that the disclosure of this encapsulation strategy will permit the PSC community to carry out extensive lifetime stability analyses, allowing the advancement of the PSC technology and its commercialization.