Unravelling the Impact of Buried Interface Voids on Hysteresis in Perovskite Solar Cells via Opto-Electro-Ionic Simulation

Abstract

Understanding the microscopic origins of performance hysteresis in perovskite solar cells is essential for achieving high performance and long-term stability. Herein, we develop an opto-electro-ionic model to systematically investigate the coupling between buried interface voids and ion migration in n-i-p structured perovskite solar cells. The results reveal that buried interface voids, as static geometric defects, not only disrupt charge transport pathways and introduce non-radiative recombination, but also disturb the electric field, thereby modulating ion redistribution and exacerbating hysteresis.Furthermore, ion concentration dominates the performance-limiting mechanism, exerting a more significant influence on device hysteresis behavior than carrier mobility. Specifically, high ion concentrations induce severe electric field screening and enhanced recombination that cannot be compensated for by increasing mobility. For void geometry, wide voids would reduce power conversion efficiency, whereas narrow voids present higher PCE at the cost of more pronounced hysteresis.Ultimately, achieving high-performance, hysteresis-free PSCs requires the synergistic mitigation of interface voids and ion migration. This work provides a quantitative physical framework and essential design principles for controlling the ionic environment and optimizing interfacial structures, thereby facilitating the development of efficient and stable PSCs.