  The stability of perovskite solar cells is closely related to the defects in
perovskite crystals, and there are a large number of crystal defects in the
perovskite thin films prepared by the solution method, which is not conducive
to the commercial production of PSCs. In this study, resveratrol(RES), a green
natural antioxidant abundant in knotweed and grape leaves, was introduced into
perovskite films to passivate the defect. RES achieves defect passivation by
interacting with uncoordinated Pb2+ in perovskite films. The results show that
the quality of the perovskite film is significantly improved, and the energy
level structure of the device is optimized, and the power conversion efficiency
of the device is increased from 21.62% to 23.44%. In addition, RES can hinder
the degradation of perovskite structures by O2- and CO2- free radicals, and the
device retained 88% of its initial PCE after over 1000 hours in pure oxygen
environment. The device retains 91% of the initial PCE after more than 1000
hours at 25{\deg}C and 50+5% relative humidity. This work provides a strategy
for the use of natural and environmentally friendly additives to improve the
efficiency and stability of devices, and provides an idea for the development
of efficient, stable and environmentally friendly PSCs.
