Ionic Defect Analysis and Suppression for Highly Efficient and Stable Perovskite Solar Cells and Mini-Modules

Abstract

Solution-processed organohalide perovskite solar cells have pushed power-conversion efficiencies to new heights, but solution routes also introduce a significant number of defects that limit both the performance and stability. In particular, lattice point defects in perovskites serve as nonradiative recombination centers, introduce midgap states, and accelerate device degradation. Although surface-passivation and shallow-trap mitigation have driven marked PCE gains, deep-level traps lurking inside the film remain poorly understood. In this work, we turn to temperature-dependent deep-level transient spectroscopy (T-DLTS) to reveal the full defect spectrum in working devices. Building on this understanding, we designed a targeted additive protocol that suppresses deep traps and elevates both efficiency and durability. The resulting cells deliver 23.36% PCE (20.68% for modules) and sustain their performance under continuous 1-sun illumination, underscoring the critical role of deep-trap management in enabling scalable and reliable perovskite photovoltaics.