2022 Fiscal Year Final Research Report
Unique optical properties by electronic structure modulation of solids under high pressure
| Project/Area Number |
19H02798
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Review Section |
Basic Section 36010:Inorganic compounds and inorganic materials chemistry-related
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| Research Institution | Kyoto University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
村上 裕美子 (片山裕美子) 東京大学, 大学院総合文化研究科, 助教 (60748680)
上田 純平 京都大学, 人間・環境学研究科, 助教 (90633181)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Keywords | 高圧光物性 / ペロブスカイト / d-d遷移 / 蛍光体 / 長残光 / 5d-4f遷移 / ガーネット / ダイヤモンドアンビルセル |
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| Outline of Final Research Achievements |
Changing the electronic structure of matters by pressure and the accompanying changes in optical properties attract much interest. We report the change in energy position of the host conduction band and the crystal field splitting of the Ce3+:5d excited level in YAGG:Ce3+ by applying pressure, which results in the red shift of Ce3+:5d-4f luminescence and increase of quenching temperature as well as dramatic change in the persistent luminescence performance by either Cr3+ or Yb3+ codoping into the phosphors. The different trap depths formed by Cr3+ and Yb3+ affect the initial persistent luminescence intensity and duration. For the Yb3+ codoped phosphor, the slope of persistent decay curve becomes more gentle with increasing pressure, while by Cr3+ codoping the slope becomes steeper. The results indicate that the trap depth of Yb3+ becomes deeper and that of Cr3+ becomes shallower with increasing pressure. Based on the pressure dependence, the electronic structures were discussed.
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| Free Research Field |
無機材料科学，光機能性材料
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| Academic Significance and Societal Importance of the Research Achievements |
これまで多くの蛍光体，半導体材料の光物性研究は，化学組成・結晶構造と温度を変数として物性調査を行う研究が主であった．しかし物質の化学ポテンシャルμが圧力，温度双方の関数であるように，固体のμに相当するFermiエネルギーや固体電子構造パラメータ全般も両者の関数である．本研究では蛍光体材料を対象とし，温度のみならず圧力を変化させた時の電子構造変化によって誘起される新しい光物性の発現を実証し，その機構を電子構造変化の観点からの解明を試みた．蛍光体材料は，ディスプレイ，放射線検出器，LED照明など生活のあらゆるところで重要な材料であり，この様な材料基礎物性研究は新材料の開発に資する．
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