A Functional Biological Molecule Restores the PbI 2 Residue-Induced Defects in Two-Step Fabricated Perovskites.

Coating the perovskite layer via a two-step method is an adaptable solution for industries compared to the anti-solvent process. But what about the impact of unreacted PbI? Usually, it is generated during perovskite conversion in a two-step method and considered beneficial within the grain boundaries, while also being accused of enhancing the interface defects and nonradiative recombination. Several additives are mixed in PbI precursors for the purpose of improving the perovskite crystallinity and hindering the Pb defects. Herein, in lieu of adding additives to the PbI, the effects of the PbI residue via the electron transport layer/perovskite interface modification are explored. Consequently, by introducing artemisinin decorated with hydrophobic alkyl units and a ketone group, it reduces the residual PbI and improves the perovskites' crystallinity by coordinating with Pb. In addition, artemisinin-deposited perovskite enhances both the stability and efficiency of perovskite solar cells by suppressing nonradiative recombination.