Aging phenomena of backsheet materials of photovoltaic systems for future zero-carbon energy and the improvement pathway

The insulation degradation in polymeric backsheets has been identified as a main cause of catastrophic accidents induced by short circuit or ground faults in photovoltaic module. To ensure quality, the photovoltaic industry is therefore faced with urgent demand in discovering degradation mechanisms. Moreover, the development of environmental-friendly backsheets and the establishment of backsheets recycling specifications are vital to fulfilling the requirements of a future reliable photovoltaic system with improved productivity. In this review, we innovatively summarize the detection methods of insulation deterioration from the viewpoints of spectroscopic, thermal and mechanical approaches. The corresponding ambient conditions in measurement and their accelerating effect on the degradation of photovoltaic backsheets are discussed. Subsequently, emerging novel materials and structures for enhancing insulation properties, anti-aging performance and optical-electrical energy conversion efficiency of photovoltaic cell are summarized. It offers a comprehensive strategy to design materials with optimal structures in photovoltaic module for a future zero-carbon energy system.