Illustration from Scientific Research

A schematic band diagram of the HTL (red)/perovskite (purple)/ETL (blue) stacks at short-circuit conditions, highlighting the accumulation of cation vacancies at the HTL (p-)interface (red squares) that leads to enhanced hole ('+') circles) accumulation and electron ('−' circles) accumulation close to the HTL. The interfacial (R interface) and bulk recombination rate (R bulk) are indicated by the purple arrows. The inset in b reveals the ion-free case where the dashed black line shows the QFLS. Here, EC and EV refer to the conduction and valence band, respectively.

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