Minimizing Buried Interface Energy Losses via Urea Phosphate Derivatives Enable High‐Efficiency Carbon‐Based Mesoscopic Perovskite Solar Cells

vacancy defects in the perovskite, respectively. Furthermore, GUP helps slow down the perovskite crystallization, promotes pore filling, reduces residual stress in the device, and optimizes energy level alignment. Consequently, the power conversion efficiency of C-MPSCs with GUP increases to 19.78%, from 18.22% of the control devices. C-MPSCs with GUP exhibit excellent stability in air storage, thermal aging, and damp heat stability tests. The study provides a novel approach to eliminate nonradiative recombination losses at the buried interfaces of C-MPSCs.