Buried Interface Engineering for MAPbI₃ Perovskite Solar Cells by the Novel Carbon Nitride Synergistic Strategy

Abstract

Carrier recombination, which arises from defects present at both the buried interface and throughout the bulk phase, hinders performance improvement in perovskite solar cells (PSCs). Nonetheless, the current strategies still face some pressing issues. Herein, we demonstrate a novel synergistic strategy of carbon nitride (C 3 N 3 ) as a buried modified layer and a perovskite antisolvent additive to reduce energy loss resulting from nonradiative recombination. C 3 N 3 functions serve as an interfacial modification layer that enhances electron mobility, improves interface contacts, and matches energy levels between SnO 2 and perovskite. Meanwhile, C 3 N 3 acts as an antisolvent additive in the perovskite layer, reducing defect density and modulating the energy level, which boosts both the efficiency and moisture stability of PSCs. Consequently, the target devices achieve a remarkable power conversion efficiency of 21.43%, with unencapsulated devices retaining 90% of their initial value after operating 1000 h. These integrated strategies provide a promising method for simultaneously reducing interfacial and bulk defects, with potential application in other photoelectronic devices.