Understanding Structural Distortions in the Formation of Self-Trapped Excitons in White-Light Emitting Halide Perovskites via UV Pump–XFEL Probe Spectroscopy

抄録

　White-light photoluminescence (PL) from 2D halide perovskites originates from distinct self-trapped exciton (STE) states. Ultrafast optical spectroscopy established PL timescales, yet structural signatures of STE are elusive. Here, we performed UV pump–Br K-edge X-ray absorption spectroscopy probe of layered emitters (EDBE)PbBr₄ and (PEA)₂PbBr₄ to discern electronic and structural contributions.