Inorganic Buffer and Sputtered ITO Diffusion Barrier for Suppressing Lamination‑Induced Degradation in PSCs

Lamination protects perovskite solar cells (PSCs) but its high temperature and pressure can accelerate device degradation. We replace the conventional organic buffer (BCP) with inorganic SnO₂ and introduce a room‑temperature sputtered amorphous ITO (a‑ITO) diffusion barrier beneath Ag. SnO₂ improves thermal robustness during 140°C glass‑to‑glass lamination and enhances Voc via better interfacial contact at ~10 min pressing. The a‑ITO barrier suppresses Ag diffusion and AgI formation, yielding markedly reduced losses in Jsc and Voc under 12 h damp‑heat stress. Devices with ITO retain ~60% of initial PCE versus ~25% for Ag‑only controls, without increasing series resistance. This inorganic stack enables simultaneous process durability and long‑term operational stability.