Comparative evaluation of stability and recyclability of readily available encapsulants for perovskite solar cells

This work compares encapsulants for perovskite solar cells (PSCs) considering stability, ease of fabrication, affordability, and impact on end-of-life management. PSCs have emerged as a promising photovoltaic technology due to their low fabrication costs and high efficiencies, yet their long-term stability remains a challenge. The degradation of PSCs is accelerated by external stressors such as moisture, oxygen, and heat, and encapsulation plays a key role in their mitigation. Despite the growing interest in PSC recycling, there is a notable lack of studies addressing PSC encapsulants and their impact on device recyclability. For effective end-of-life management, cell components need to be efficiently separated, and thus the impact of encapsulation on dismantling is critical. The inconsistency of testing methods in the literature makes comparison of encapsulants difficult. Besides comparing literature alternatives, this work also experimentally explores a variety of encapsulants which are selected based on criteria that they need to be inexpensive, readily available, and simple to apply without specialized equipment. Herein, 13 encapsulants are initially evaluated through their moisture-blocking capabilities and discoloration during accelerated aging. The three most promising candidates are used to encapsulate PSCs and are evaluated using a highly demanding accelerated damp aging test. Only one tested material, epoxy quartz-based 2-component glue, passed this test: after 1000 h at 25°C and 85% RH, PSCs encapsulated with it retained 112% of their initial efficiency, whereas silicone, ethylene-vinyl acetate (EVA), and unencapsulated reference cells retained less than 13%. This work highlights that PSC encapsulation requires further study, particularly regarding end-of-life management.