Improvement in solar cells efficiency with luminescent downshifting nanocomposite lamination: A green alternative for ethylene-vinyl acetate

Commercializing emerging photovoltaic (PV) technologies is hindered by challenges such as performance instability, short lifespans, and reliance on expensive, non-eco-friendly materials. Key contributors to PV degradation and instability include ultraviolet (UV) radiation and environmental factors like humidity, air, and temperature. While UV-related issues can be mitigated through luminescent downshifting (LDS), environmental hazards are typically addressed through encapsulation. The industry standard, ethylene-vinyl acetate (EVA), used for encapsulating and laminating solar cells, is both expensive and toxic, and lacks effective UV protection. To overcome these challenges, an environmentally friendly, cost-effective LDS nanocomposite based on carbon dots (CDs) and epoxy was developed in this study, which can be applied as a laminating layer for PVs. This nanocomposite efficiently converts ultraviolet photons into visible light, enhancing the power conversion efficiency (PCE) of silicon solar cells by 1.65% and achieving a current density gain of 8.33 mAcm(-2). The synthesized carbon dots exhibit a photoluminescence quantum yield of 34%. The resulting PCE improvement is significant, as it could lead to a bill of materials (BoM) cost reduction of approximately 1.58% for mono- crystalline silicon PV modules, factoring in the cost of nanocomposite application. This translates to a cost reduction from $0.10/watt to $0.098418/watt. This innovative nanocomposite not only provides LDS functionality but also serves as a robust, industrially scalable encapsulant, offering a green and economically viable solution for improving the stability and performance of PV devices and other optoelectronic applications.