Investigation of quenching process by hole transfer for phosphors doped with rare earth and transition metal ions

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H02438
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: Japan Advanced Institute of Science and Technology (2022-2023); Kyoto University (2020-2021)
• Principal Investigator: Ueda Jumpei 北陸先端科学技術大学院大学, 先端科学技術研究科, 准教授 (90633181)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 蛍光体 / 消光 / ホール移動 / 長残光蛍光体 / 蓄光材料

Outline of Final Research Achievements

Mn4+-doped and Eu3+-doped red phosphors have attracted much attention as white LED phosphors because of the sharp red line luminescence. However, the temperature quenching in these red phosphors is still not elucidated in detail. In this study, we try to demonstrate the existence of hole transfer quenching. In the prepared Y2O2S:Eu3+, the thermoluminescence excitation (TLE) spectra at different charging temperatures were investigated. As a result, the hole transfer from the excited state of Eu3+ was observed. From the relationship between the temperature dependence of the luminescence intensity and TLE spectra, we successfully demonstrate the hole thermal ionization quenching process.

Free Research Field

無機化学

Academic Significance and Societal Importance of the Research Achievements

蛍光体において、励起光により発光中心イオンからホールが移動して消光するプロセスを証明した例はほとんどなく学術的にも非常に意義のある研究である。また、白色LED用の赤色蛍光体として期待されているEu3+蛍光体の消光プロセスが解明されることにより、高効率かつ温度消光しにくい赤色蛍光体の材料設計が可能になり、今後の新規蛍光体開発に繋がり、社会的意義も大きいと言える。