Study of relationship between luminescence properties and surface defect in long afterglow phosphors

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K15030
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: Niigata University (2021); Chuo University (2020)
• Principal Investigator: Watanabe Mizuki 新潟大学, 自然科学系, 助教 (60847987)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: 長残光蛍光体 / 表面欠陥 / 発光特性

Outline of Final Research Achievements

In this study, we investigated the relationship between surface defects and luminescence and afterglow properties of alkaline earth aluminate phosphors doped with divalent europium ions (Eu2+) as luminescent ions.　Especially, in SrAl2O4 : Eu2+, luminescence properties changed significantly depending on the amount of Eu2+ solid solution, suggesting a relationship between the crystal structure and luminescence properties. We confirmed that the luminescence properties change by increasing the amount of defects. We attempted to evaluate the luminescence properties in the absence of the influence of surface adsorbates using a unique glass cell unit, suggesting that the change in luminescence properties in SrAl2O4 : Eu2+ is due to the increase or change in the amount of surface defects, rather than to the influence of surface adsorbates.

Free Research Field

無機材料化学

Academic Significance and Societal Importance of the Research Achievements

本課題により、SrAl2O4:Eu2+をはじめとした長残光蛍光体において、表面に吸着物質の無い状態で、物質の欠陥のみの発光特性を評価することに成功し、その欠陥状態により、発光特性が変化することが明らかとなった。ほとんど未解明であった材料自体の表面欠陥が光学・残光特性に与える影響を調査する方法を考案し、実際にその影響を調査した本課題で得られた知見は、バイオイメージング材料としての応用など、今後新たに応用用途が広がっていくことが予想される長残光蛍光体について、一つの材料設計を示す鍵となることが期待される。