Efficient and Stable Flexible Organic Solar Cells via the Enhanced Optical-Thermal Radiative Transfer

摘要

Heating is a knotty factor contributing to device degradation of flexibleorganic solar cells (FOSCs), and thermal regulation plays a crucial role in therealization of long operational lifetime. Herein, a passive cooling strategy forstable FOSCs is proposed by boosting the optical-thermal radiative transferto reduce the insufficient thermal dissipation and the elevated temperaturecaused by irradiation-induced heating, while retaining their flexibility andportability. A spectrally selective coupling structure consisting of subwavelengthhemisphere pattern and distributed Bragg reflector is integrated intoFOSCs to collectively enhance out-coupling of infrared radiation and limitnear-infrared absorption-induced heat generation, leading to a reduced heatpower intensity of 292.5 W cm~(?2) and the decreased working temperature by9.6 ℃ under outdoor sunlight irradiation. The D18:Y6:PC71BM-based FOSCsachieve a power conversion efficiency of over 17 with a prolonged T_(80) lifetimeas long as one year under real outdoor working conditions. These resultsrepresent a new opportunity for enhancing the operational stability of FOSCs.