Dual Metal-Assisted Defect Engineering towards High-Performance Perovskite Solar Cells

摘要

Perovskite solar cells (PSCs) have witnessed an unprecedentedly rapid development,especially in terms of power conversion efficiency (PCE). However,the solution-processed perovskite films inevitably possess numerous crystallographicdefects (e.g., halide vacancies), which has been shown to incurnon-radiative charge recombination and ion migration, thus limiting theenhancement of the PCE and stability of PSCs. Here, a novel dual metal (i.e.,divalent and monovalent metal ions) modification strategy is reported forsimultaneously reducing the defects, immobilizing the halide anions, and preventingion loss from perovskite during post-annealing process. Accordingly,this strategy significantly reduces non-radiative recombination, enhancingthe PCE by ≈12% and mitigating the current density-voltage (J–V) hysteresiseffect in resultant devices compared to undoped counterparts. As a result, achampion PCE exceeding 22% and a high open-circuit voltage (V_(oc)) of 1.16 Vis obtained for dual metal ions-modified PSCs. The optimized devices alsoexhibit extended lifespan upon the dual metal treatment. The study providesa new defect engineering strategy toward more efficient and stable perovskitephotovoltaics.