Perovskite quantum dots (PQDs) are considered one of the most promising candidates for next-generation solar cells due to their excellent optoelectronic properties and solution processability. However, the photoelectric properties of PQDs degrade severely during storage due to dynamic ligand binding, which primarily affects photovoltaic applications. Zhang Xiaoliang et al. from Beihang University found that in situ defect passivation treatment can effectively rejuvenate aged PQDs. Through systematic experimental research and theoretical calculations, they fundamentally understand the reasons for the recovery of the photoelectric properties of aged PQDs.

The results show that I3− anions generated from tetraoctylammonium iodide and iodine can be firmly anchored to the surface defects of aged PQDs, which greatly reduces non-radiative recombination of photogenerated charge carriers. At the same time, the defect repair treatment can also refresh the morphology of aged PQDs, thereby improving the stacking orientation of PQD solids and improving carrier transport in PQD solids.

Therefore, by using defect repair treatment, the efficiency of perovskite quantum dot solar cells (PQDSCs) reached as high as 15.88%, comparable to PQDSCs fabricated with fresh PQDs. Meanwhile, the stability of PQDSCs prepared with the regenerated PQDs is also greatly improved.