Unraveling Abnormal Thermal Quenching of Sub‐Gap Emission in β‐Ga2O3
Abstract In this work, the optical transition of self‐trapped excitons (STEs) and the emergent green emission in β‐Ga2O3 samples with/without Sn impurities at various doping levels have been investigated via temperature‐ and power‐dependent photoluminescence. The ultraviolet (UV) emissions ≈ 3.40 eV...
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Wiley-VCH
2025-01-01
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| Series: | Advanced Electronic Materials |
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| Online Access: | https://doi.org/10.1002/aelm.202400315 |
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| author | Zhengpeng Wang Fei Tang Fang‐Fang Ren Hongwei Liang Xiangyuan Cui Shijie Xu Shulin Gu Rong Zhang Youdou Zheng Jiandong Ye |
| author_facet | Zhengpeng Wang Fei Tang Fang‐Fang Ren Hongwei Liang Xiangyuan Cui Shijie Xu Shulin Gu Rong Zhang Youdou Zheng Jiandong Ye |
| author_sort | Zhengpeng Wang |
| collection | DOAJ |
| description | Abstract In this work, the optical transition of self‐trapped excitons (STEs) and the emergent green emission in β‐Ga2O3 samples with/without Sn impurities at various doping levels have been investigated via temperature‐ and power‐dependent photoluminescence. The ultraviolet (UV) emissions ≈ 3.40 eV unanimously exhibit an excitonic nature related to STEs and typical negative thermal quenching (NTQ) characters. The NTQ activation energy decreases from 103.56 to 42.37 meV with the increased electron concentration from 2.1 × 1016 to 6.7 × 1018 cm−3, indicative of the reduced energy barrier that electrons should overcome to form stable STEs due to the lift‐up of Fermi level. In comparison, the green emissions ≈ 2.35 eV with two quenching channels are observed only in samples with Sn impurities at cryogenic temperatures. One channel is the nsnp‐ns2 transition of Sn2+, the other is donor‐acceptor pair recombination via (2VGa‐Sni)2− complex, which is energetically favorable as evidenced by density functional theory calculations. The semi‐classical quantum theory models fitting proves the transition from green to UV emissions with elevated temperature. The enhanced STEs emission with distinguished NTQ effect strengthens evidence that the stable polarons inherently limit the transport of holes in Ga2O3, and also support the potential of Ga2O3 materials for the development of UV optoelectronics. |
| format | Article |
| id | doaj-art-4caf514b4ac0425cb27fa39fbea4d0ea |
| institution | Kabale University |
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| language | English |
| publishDate | 2025-01-01 |
| publisher | Wiley-VCH |
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| series | Advanced Electronic Materials |
| spelling | doaj-art-4caf514b4ac0425cb27fa39fbea4d0ea2025-01-10T13:40:16ZengWiley-VCHAdvanced Electronic Materials2199-160X2025-01-01111n/an/a10.1002/aelm.202400315Unraveling Abnormal Thermal Quenching of Sub‐Gap Emission in β‐Ga2O3Zhengpeng Wang0Fei Tang1Fang‐Fang Ren2Hongwei Liang3Xiangyuan Cui4Shijie Xu5Shulin Gu6Rong Zhang7Youdou Zheng8Jiandong Ye9School of Electronic Science and Engineering Nanjing University Nanjing 210023 ChinaJiangsu Key Laboratory of Advanced Laser Materials and Devices School of Physics and Electronic Engineering Jiangsu Normal University Xuzhou 221116 ChinaSchool of Electronic Science and Engineering Nanjing University Nanjing 210023 ChinaSchool of Physics and Optoelectronic Engineering Dalian University of Technology Dalian 116024 ChinaAustralian Centre for Microscopy and Microanalysis, and School of Aerospace Mechanical and Mechatronic Engineering The University of Sydney Sydney NSW 2006 AustraliaDepartment of Optical Science and Engineering School of Information Science and Technology Fudan University Shanghai 200438 ChinaSchool of Electronic Science and Engineering Nanjing University Nanjing 210023 ChinaSchool of Electronic Science and Engineering Nanjing University Nanjing 210023 ChinaSchool of Electronic Science and Engineering Nanjing University Nanjing 210023 ChinaSchool of Electronic Science and Engineering Nanjing University Nanjing 210023 ChinaAbstract In this work, the optical transition of self‐trapped excitons (STEs) and the emergent green emission in β‐Ga2O3 samples with/without Sn impurities at various doping levels have been investigated via temperature‐ and power‐dependent photoluminescence. The ultraviolet (UV) emissions ≈ 3.40 eV unanimously exhibit an excitonic nature related to STEs and typical negative thermal quenching (NTQ) characters. The NTQ activation energy decreases from 103.56 to 42.37 meV with the increased electron concentration from 2.1 × 1016 to 6.7 × 1018 cm−3, indicative of the reduced energy barrier that electrons should overcome to form stable STEs due to the lift‐up of Fermi level. In comparison, the green emissions ≈ 2.35 eV with two quenching channels are observed only in samples with Sn impurities at cryogenic temperatures. One channel is the nsnp‐ns2 transition of Sn2+, the other is donor‐acceptor pair recombination via (2VGa‐Sni)2− complex, which is energetically favorable as evidenced by density functional theory calculations. The semi‐classical quantum theory models fitting proves the transition from green to UV emissions with elevated temperature. The enhanced STEs emission with distinguished NTQ effect strengthens evidence that the stable polarons inherently limit the transport of holes in Ga2O3, and also support the potential of Ga2O3 materials for the development of UV optoelectronics.https://doi.org/10.1002/aelm.202400315negative thermal quenchingPhotoluminescenceself‐trapped excitonsultrawide bandgap semiconductors |
| spellingShingle | Zhengpeng Wang Fei Tang Fang‐Fang Ren Hongwei Liang Xiangyuan Cui Shijie Xu Shulin Gu Rong Zhang Youdou Zheng Jiandong Ye Unraveling Abnormal Thermal Quenching of Sub‐Gap Emission in β‐Ga2O3 Advanced Electronic Materials negative thermal quenching Photoluminescence self‐trapped excitons ultrawide bandgap semiconductors |
| title | Unraveling Abnormal Thermal Quenching of Sub‐Gap Emission in β‐Ga2O3 |
| title_full | Unraveling Abnormal Thermal Quenching of Sub‐Gap Emission in β‐Ga2O3 |
| title_fullStr | Unraveling Abnormal Thermal Quenching of Sub‐Gap Emission in β‐Ga2O3 |
| title_full_unstemmed | Unraveling Abnormal Thermal Quenching of Sub‐Gap Emission in β‐Ga2O3 |
| title_short | Unraveling Abnormal Thermal Quenching of Sub‐Gap Emission in β‐Ga2O3 |
| title_sort | unraveling abnormal thermal quenching of sub gap emission in β ga2o3 |
| topic | negative thermal quenching Photoluminescence self‐trapped excitons ultrawide bandgap semiconductors |
| url | https://doi.org/10.1002/aelm.202400315 |
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