Interfacial Dynamics In article number 2207835, Hsien-Yi Hsu and co-workers systematically study interfacial dynamics of bandgap funnelling in MA3Bi2Cl9−xIx perovskites using temperature-dependent transient photoluminescence and electrochemical voltammetric techniques. The photophysical and (photo)electrochemical phenomena of solid–solid and solid–liquid interfaces are therefore confirmed. The importance of this work is to explore the intrinsic and interfacial properties of semiconductor materials for elucidating the correlation between material characterization and device performance.