Yanmei He
Postdoctoral fellow
Unveiling Mechanism of Temperature-Dependent Self-Trapped Exciton Emission in 1D Hybrid Organic–Inorganic Tin Halide for Advanced Thermography
Author
Summary, in English
Lead-free hybrid metal halide phosphors/crystals showing self-trapped exciton (STE) emission have been recently explored for thermography due to the strong temperature dependence of their photoluminescence (PL) lifetime (τ). However, realizing high-spatial-resolution thermography using polycrystalline powders or crystals presents a challenge. Moreover, the underlying mechanism of temperature-dependent STE remains elusive. Herein, a homogeneous 1D ODASn2I6 (ODA, 1,8-octanediamine) nm-scale thin film exhibiting efficient STE emission is investigated. The PL decay shows a strong temperature dependence from 275 K (τ ≈ 1.31 µs) to 350 K (τ ≈ 0.65 µs) yielding a thermal sensitivity of 0.014 K−1. By employing temperature-dependent transient absorption spectroscopy, detailed information is obtained about the relaxation processes prior to the STE formation. Simultaneous analyses of steady-state and time-resolved spectroscopies lead to a self-consistent model where the thermally activated phonon-assisted nonradiative pathway explains the temperature dependence of the PL lifetime via a conical intersection between the ground state and STE potential energy surfaces. Finally, a discernible 50 ns variation in PL lifetimes across different heated regimes over a distance of 1.15 mm is successfully demonstrated with fluorescence lifetime imaging microscopy, underscoring the substantial potential of ODASn2I6 thin film for high-spatial-resolution thermography.
Department/s
- LU Profile Area: Light and Materials
- LTH Profile Area: Nanoscience and Semiconductor Technology
- Chemical Physics
- NanoLund: Centre for Nanoscience
- LTH Profile Area: Photon Science and Technology
Publishing year
2025
Language
English
Publication/Series
Advanced Optical Materials
Volume
13
Issue
2
Document type
Journal article
Publisher
John Wiley & Sons Inc.
Topic
- Materials Chemistry
- Physical Chemistry (including Surface- and Colloid Chemistry)
- Condensed Matter Physics (including Material Physics, Nano Physics)
Keywords
- exciton dynamics
- hybrid organic–inorganic tin halide
- self-trapped exciton
- thermography
- ultrafast spectroscopy
Status
Published
ISBN/ISSN/Other
- ISSN: 2195-1071