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The ionoluminescence of strontium titanate (SrTiO3) under the intense electronic excitation produced by 3 MeV H, 19 MeV Si, and 19 MeV Cl ions was investigated for temperatures between 30 and 100 K. In addition to previously reported emission bands centered at 2.0 eV, 2.5 eV, and 2.8 eV, an asymmetric, narrow emission band centered at 3.15 eV was observed for the first time under ion irradiation. The 3.15 eV band appeared only under heavy ion irradiation (19 MeV Si and Cl) and at temperatures below ~70 K. The absence of the 3.15 eV emission under proton irradiation indicates that impurities and the pre-irradiation defect population likely play little or no role in the emission process, while electronic excitation density does. At the same time, the absence of fluence-dependent growth in the yield suggests that irradiation-induced defects are also unlikely to be the main cause of the emission. Upon comparing the proton induced ionoluminescence, heavy ion induced ionoluminescence, and available literature on low temperature photoluminescence of strontium titanate, a self-consistent interpretation emerges, where the 3.15 eV emission is associated with the recombination of large polarons.
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Temperature dependence of cathodoluminescence emission in irradiated Si-doped β-Ga2O3
Temperature dependent continuous and time-resolved cathodoluminescence measurements were employed to understand the luminescence from Si-doped β-Ga2O3 prior to irradiation and after 10 MeV proton and 18 MeV alpha-particle irradiation. The shape and location of the luminescence components [ultraviolet luminescence (UVL′) at 3.63 eV, UVL at 3.3 eV, and blue-luminescence at 2.96 eV] obtained from Gaussian decomposition did not change in either width or peak location, indicating that new radiation-induced trap-levels were non-radiative in nature between the 4.5 and 310 K temperature range. Activation energies, associated with thermal quenching of UVL′ and UVL bands, show temperature dependence, suggesting ionization of shallow Si-donors and a thermally activated non-radiative process.
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- PAR ID:
- 10597147
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- AIP Advances
- Volume:
- 11
- Issue:
- 12
- ISSN:
- 2158-3226
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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