Extrinsic nature of the broad photoluminescence in lead iodide-based Ruddlesden–Popper perovskites

Abstract

The Ruddlesden–Popper type of halide perovskites are gaining interest but the origin of their broad band emission remains elusive. Here Kahmann et al. suggest that in-gap states, instead of the commonly believed self-trapped excitons, are responsible for the broad band emission in crystalline samples.