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Updated: Sep 11, 2025
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Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
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Oxygen-Vacancy-Driven Persistent Luminescence in Mn2+-Doped MgGeO3: Insights from X-Ray Absorption Fine Structure
Sherry Cao1, Yihong Liu1, Ruoxin Deng1
1Department of Chemistry, Western University, 1151 Richmond Street, London, N6A5B7, Canada.
Summary
This study reveals that the duration of persistent luminescence in Mn2+-doped MgGeO3 phosphors is directly linked to the local germanium-oxygen coordination number. In-house X-ray absorption spectroscopy confirms this structural correlation.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Luminescence
Background:
- Mn2+-doped MgGeO3 (MMGO) exhibits near-infrared persistent luminescence (PersL).
- Luminescence decay in MMGO is hypothesized to relate to vacancies in the MgGeO3 host, possibly involving germanium (Ge), but direct evidence is lacking.
Purpose of the Study:
- To investigate the local Ge environment in MMGO phosphors with varying afterglow durations.
- To establish direct correlations between structural properties and persistent luminescence characteristics.
- To validate the use of in-house X-ray absorption fine structure (XAFS) spectroscopy for advanced materials research.
Main Methods:
- Synthesis of MMGO submicron-sized particles via a hydrothermal method.
- Characterization using Ge K-edge X-ray absorption fine structure (XAFS) spectroscopy with an in-house spectrometer.
- Analysis of XAFS spectra to determine the local Ge environment, including coordination numbers.
Main Results:
- Persistent luminescence duration is directly correlated with the Ge-O coordination number in MMGO.
- The introduction of Li+ codopants extends PersL duration without affecting the Ge-O coordination.
- In-house XAFS data quality is comparable to synchrotron-based measurements.
Conclusions:
- The Ge-O coordination number is a critical factor governing the persistent luminescence duration in MMGO.
- In-house XAFS systems are capable of generating high-quality data for detailed materials analysis.
- This research provides insights into the structural mechanisms underlying luminescence in MMGO phosphors.
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