Proceedings of 13th Conference on Hybrid and Organic Photovoltaics (HOPV21)
Publication date: 11th May 2021
Ion migration in metal halide perovskites is an important contributing factor, for many unusual phenomena in photovoltaic devices, such as current-voltage hysteresis, and photoinduced phase separation and transformations. It is now well established that metal halide perovskites are mixed ionic-electronic conductors and halide ions are mobile at room temperature. During device operation, various physical stimuli like light, heat, pressure, and applied bias can affect the distribution and movement of ions. However, the impact of each stimulus is poorly understood. Using first-principles density functional theory (DFT) calculations, we simulate the halide ion migration mediated by vacancies in CsPbX3 (X = Cl, Br, I) and systematically control the electronic, chemical, and mechanical conditions. We explore the potential energy landscape for chemical transport including the activation energies of ions migration and how these device-relevant conditions influence the path and the energy barrier of ion migration.