Long-Lasting Nanophosphors Applied to UV-Resistant and Energy Storage Perovskite Solar Cells

Recently, considerable progress is achieved in lab prototype perovskite solar cells (PSCs); however, the stability of outdoor applications of PSCs remains a challenge due to the high sensitivity of perovskite material under moist and ultraviolet (UV) light conditions. In this work, the UV photostability of PSC devices is improved by incorporating a photon downshifting layer-SrAl2O4: Eu2+, Dy3+ (SAED)-prepared using the pulsed laser deposition approach. Light-induced deep trap states in the photoactive layer are depressed, and UV light-induced device degradation is inhibited after the SAED modification. Optimized power conversion efficiency (PCE) of 17.8% is obtained through the enhanced light harvesting and reduced carrier recombination provided by SAED. More importantly, a solar energy storage effect due to the long-persistent luminescence of SAED is obtained after light illumination is turned off. The introduction of downconverting material with long-persistent luminescence in PSCs not only represents a new strategy to improve PCE and light stability by photoconversion from UV to visible light but also provides a new paradigm for solar energy storage.