Unravelling the Interfacial Dynamics of Bandgap Funneling in Bismuth-Based Halide Perovskites

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

11 Scopus Citations
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  • Guohua Jia
  • Kuan-Chen Cheng
  • Haisheng Song
  • Mingjian Yuan
  • Juan Carlos Colmenares
  • Hsien-Yi Hsu


Original languageEnglish
Article number2207835
Journal / PublicationAdvanced Materials
Issue number2
Online published17 Oct 2022
Publication statusPublished - 12 Jan 2023


An environmentally friendly mixed-halide perovskite MA3Bi2Cl9−xIx with a bandgap funnel structure has been developed. However, the dynamic interfacial interactions of bandgap funneling in MA3Bi2Cl9−xIx perovskites in the photo-electrochemical (PEC) system remain ambiguous. In light of this, single- and mixed-halide lead-free bismuth-based hybrid perovskites—MA3Bi2Cl9−yIy and MA3Bi2I9 (named MBCl-I and MBI)—in the presence and absence of the bandgap funnel structure, respectively, are prepared. Using temperature-dependent transient photoluminescence and electrochemical voltammetric techniques, the photophysical and (photo)electrochemical phenomena of solid–solid and solid–liquid interfaces for MBCl-I and MBI halide perovskites are therefore confirmed. Concerning the mixed-halide hybrid perovskites MBCl-I with a bandgap funnel structure, stronger electronic coupling arising from an enhanced overlap of electronic wavefunctions results in more efficient exciton transport. Besides, MBCl-I's effective diffusion coefficient and electron-transfer rate demonstrate efficient heterogeneous charge transfer at the solid–liquid interface, generating improved photoelectrochemical hydrogen production. Consequently, this combination of photophysical and electrochemical techniques opens up an avenue to explore the intrinsic and interfacial properties of semiconductor materials for elucidating the correlation between material characterization and device performance.

Research Area(s)

  • interfacial dynamics, lead-free halide perovskites, photoelectrocatalysis