Fabricate the Compressive-Strained Perovskite Solar Cells through the Lattice-Matching Chelation

Abstract

Fabricating compressive-strained perovskite films can boost the efficiency and stability of perovskite solar cells (PSCs). However, compositional engineering toward the conversion of surface tension strain to compressive strain rarely succeeds. Herein, we propose an effective lattice-matching chelation strategy to modulate the strain of the crystal lattice of perovskite films. Detailed investigations show that the organic salt of bidentate imidazole (MZ-1) can firmly anchor the perovskite lattice, resulting in compressive-strained perovskite films, leading to better energy alignment, improved charge carrier transport, decreased nonradiative recombination, and lower trap state density. PSC based on MZ-1 exhibits a dramatically improved efficiency of 24.61% along with improved long-term thermal stability. Importantly, a large-area (25 cm2) integrated module achieves an efficiency of 20.53%.