Development of new all-inorganic white LED devices with persistent luminescence

• Project/Area Number: 21K14409
• 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: National Institute for Materials Science
• Principal Investigator: XU Jian 国立研究開発法人物質・材料研究機構, 若手国際研究センター, ICYSリサーチフェロー (10889918)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2022: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2021: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
• Keywords: 蛍光体 / LED / 残光 / 発光メカニズム / 白色LED / 長残光 / 透光性セラミックス / 近赤外蛍光・残光 / 単粒子診断法

Outline of Research at the Start

これまでに、残光蛍光体として商用化されているSrAl2O4:Eu2+-Dy3+は緑色例として夜間、緊急時の照明や視野誘導などに広く用いられている。一方、白色LEDの研究について、高効率及び高演色性の蛍光材料の研究・開発が盛んに行われているが、長残光透光性セラミックスを用いた「黄色長残光+白色LED」の2つの機能を兼ね備える材料開発の報告例は無い。本研究で提案する長残光機能を持った白色LEDの開発によって、通常時は「完全無機化全固体白色LED」照明設備として使用され、非常事態時では上半分の黄色長残光透光性セラミックスの長残光機能を利用し、持続的に黄色警告光を長時間発光することができる。

Outline of Final Research Achievements

In this research, we successfully prepared Gd3Al5-xGaxO12(GAGG) doped with Ce3+ and Cr3+ garnet transparent ceramics with long persistent luminescence (PersL) over 2 hours after ceasing the blue LED excitation, by utilizing the knowledge of band-gap engineering and trapping-detrapping mechanism. Based on the PersL properties, we obtained 73.8% flicker suppression in 50 Hz AC driven LED by using GAGG:Ce-Cr transparent ceramics.

Academic Significance and Societal Importance of the Research Achievements

高い光学特性を有する透光性セラミックスおよびイオン電子構造制御のバンドギャップエンジニアリングに関する学術的価値もさることながら、世界の照明機器市場に大きな影響力の高い発光効率を持つ材料の開発と応用が可能となる。本研究で提案する長残光機能を持った白色LEDの開発によって、通常時は「完全無機化白色LED」照明設備として使用され、非常事態の下では（例えば地震、津波によって引き起こされる大規模停電時）、上半分の黄色長残光透光性セラミックスの発光する機能を利用できる。このように、この材料は持続的に黄色警告光を長時間発光することができ、被災者を救済する際に非常に有用である。

Research Products

• [Int'l Joint Research] Ca' Foscari University of Venice(イタリア)
• [Int'l Joint Research] Ca' Foscari University of Venice(イタリア)
• [Journal Article] Neodymium(III)-doped Y₃Al₂Ga₃O₁₂ garnet for multipurpose ratiometric thermometry: From cryogenic to high temperature sensing (2023)
  • Author(s): Back Michele、Xu Jian、Ueda Jumpei、Tanabe Setsuhisa
  • Journal Title: Journal of the Ceramic Society of Japan Volume: 131 Issue: 4 Pages: 57-61
  • DOI: 10.2109/jcersj2.22167
  • ISSN: 1348-6535, 1882-0743
  • Year and Date: 2023-04-01
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Thermostable Europium Polymer Crystalline Spherical Beads and Their Photophysical Properties (2023)
  • Author(s): Nakanishi Takayuki、Xu Jian、Hirosaki Naoto、Takeda Takashi
  • Journal Title: Sensors and Materials Volume: 35 Issue: 2 Pages: 529
  • DOI: 10.18494/SAM4150
  • ISSN: 0914-4935, 2435-0869
  • Year and Date: 2023-02-20
  • Peer Reviewed / Open Access
• [Journal Article] Highly Thermal Stable Broadband Near-Infrared Luminescence in Ni2+-Doped LaAlO3 with Charge Compensator (2023)
  • Author(s): Ueda Jumpei、Minowa Tomoaki、Xu Jian、Tanaka Shogo、Nakanishi Takayuki、Takeda Takashi、Tanabe Setsuhisa
  • Journal Title: ACS Applied Optical Materials Volume: in press Issue: 6 Pages: 1128-1137
  • DOI: 10.1021/acsaom.3c00041
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Structural metamorphosis and photophysical properties of thermostable nano- and microcrystalline lanthanide polymer with flexible coordination chains (2023)
  • Author(s): Nakanishi Takayuki、Hirai Yuichi、Xu Jian、Takeda Takashi、Watanabe Shunsuke、Yasumori Atsuo、Hakamada Shou、Kitagawa Yuichi、Hasegawa Yasuchika
  • Journal Title: Science and Technology of Advanced Materials Volume: 24 Issue: 1 Pages: 1-11
  • DOI: 10.1080/14686996.2023.2183711
  • Peer Reviewed / Open Access
• [Journal Article] Powder synthesis and luminescence of a novel yellow-emitting Ba5Si11Al7N25: Eu2+ phosphor discovered by a single-particle-diagnosis approach for warm w-LEDs (2023)
  • Author(s): He Can、Takeda Takashi、Huang Zhaohui、Xu Jian、Chen Jun、Yi Wei、Xie Rongjun、Hirosaki Naoto
  • Journal Title: Chemical Engineering Journal Volume: 455 Pages: 140932-140932
  • DOI: 10.1016/j.cej.2022.140932
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Thermochromic Narrow Band Gap Phosphors for Multimodal Optical Thermometry: The Case of Y3+-Stabilized β-Bi2O3:Nd3+ (2022)
  • Author(s): M. Back, J. Xu, J. Ueda, A. Benedetti, S. Tanabe
  • Journal Title: Chemistry of Materials Volume: 34 Issue: 18 Pages: 8198-8206
  • DOI: 10.1021/acs.chemmater.2c01262
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Deep-red to near-infrared luminescence from Eu²⁺-trapped exciton states in YSiO₂N (2022)
  • Author(s): Kitagawa Yuuki、Ueda Jumpei、Xu Jian、Nakanishi Takayuki、Takeda Takashi、Hirosaki Naoto、Tanabe Setsuhisa
  • Journal Title: Physical Chemistry Chemical Physics Volume: 24 Issue: 7 Pages: 4348-4357
  • DOI: 10.1039/d1cp05242j
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Unraveling electron liberation from Bi2+ for designing Bi3+-based afterglow phosphor for anti-counterfeiting and flexible X-ray imaging (2022)
  • Author(s): Tianshuai Lyu, Pieter Dorenbos, Canhua Li, Silei Li, Jian Xu, Zhanhua Wei
  • Journal Title: Chemical Engineering Journal Volume: 435 Pages: 1350381-18
  • DOI: 10.1016/j.cej.2022.135038
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Effect of dopant concentration on the optical characteristics of Cr3+:ZnGa2O4 transparent ceramics exhibiting persistent luminescence (2022)
  • Author(s): Zhengfa Dai, Xinyu Mao, Qiang Liu, Danyang Zhu, Haohong Chen, Tengfei Xie, Jian Xu, Dariusz Hreniak, Martin Nikl, Jiang Li
  • Journal Title: Optical Materials Volume: 125 Pages: 1121271-7
  • DOI: 10.1016/j.optmat.2022.112127
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Fabrication and long persistent luminescence of Ce3+-Cr3+ co-doped yttrium aluminum gallium garnet transparent ceramics (2022)
  • Author(s): Liu Qiang, Wang Wenli, Dai Zhengfa, Boiko Vitalii, Chen Haohong, Liu Xin, Zhu Danyang, Xu Jian, Hreniak Dariusz, Li Jiang
  • Journal Title: Journal of Rare Earths Volume: in press Issue: 11 Pages: 1699-1705
  • DOI: 10.1016/j.jre.2022.01.017
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Near-infrared Phosphors: Photophysical Properties of Calcium-doped YSGG:Cr4+ (2021)
  • Author(s): Takayuki Nakanishi, Makoto Tsurui, Jian Xu, Nao Takahashi, Takashi Takeda, Naoto Hirosaki
  • Journal Title: Sensors and Materials Volume: 33 Issue: 6 Pages: 2227
  • DOI: 10.18494/SAM.2021.3320
  • ISSN: 0914-4935, 2435-0869
  • Year and Date: 2021-06-24
  • Peer Reviewed
• [Journal Article] Cyan-Emitting Sialon-Polytypoid Phosphor Discovered by a Single-Particle-Diagnosis Approach (2021)
  • Author(s): Jian Xu, Shiro Funahashi, Kohsei Takahashi, Takayuki Nakanishi, Naoto Hirosaki, Takashi Takeda
  • Journal Title: ECS Journal of Solid State Science and Technology Volume: 10 Issue: 11 Pages: 1160021-6
  • DOI: 10.1149/2162-8777/ac331c
  • Peer Reviewed
• [Journal Article] How Many Electron Traps are formed in Persistent Phosphors? (2021)
  • Author(s): Ueda Jumpei、Xu Jian、Takemura Shota、Nakanishi Takayuki、Miyano Shun、Segawa Hiroyo、Tanabe Setsuhisa
  • Journal Title: ECS Journal of Solid State Science and Technology Volume: 10 Issue: 11 Pages: 116003-116003
  • DOI: 10.1149/2162-8777/ac2e4e
  • Peer Reviewed / Open Access
• [Journal Article] High-Pressure Photoluminescence Properties of Cr³⁺-Doped LaGaO₃ Perovskites Modulated by Pressure-Induced Phase Transition (2021)
  • Author(s): Hua Hansen、Ueda Jumpei、Xu Jian、Back Michele、Tanabe Setsuhisa
  • Journal Title: Inorganic Chemistry Volume: 60 Issue: 24 Pages: 19253-19262
  • DOI: 10.1021/acs.inorgchem.1c03074
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Unraveling the Luminescence Quenching of Phosphors under High-Power-Density Excitation (2021)
  • Author(s): Peng Zheng, Shuxing Li, Takashi Takeda, Jian Xu, Kohsei Takahashi, Rundong Tian, Ran Wei, Le Wang, Tian-Liang Zhou, Naoto Hirosaki, Rong-Jun Xie
  • Journal Title: Acta Materialia Volume: 209 Pages: 1168131-11
  • DOI: 10.1016/j.actamat.2021.116813
  • Peer Reviewed
• [Presentation] New insights into the saturation mechanism of Ce3+/Eu2+ doped LED phosphors under high-power laser excitation (2022)
  • Author(s): 許 健, 高橋 向星, 中西 貴之, 広崎 尚登, 武田 隆史
  • Organizer: 第38回希土類討論会
• [Presentation] Discovery of New (oxy)nitride phosphors by single-particle-diagnosis approach and time-resolved spectroscopy (2022)
  • Author(s): 許 健, 舟橋 司朗, 中西 貴之, 高橋 向星, 広崎 尚登, 武田 隆史
  • Organizer: 応用物理学会第83回秋季学術講演会
• [Presentation] Discovery of New (oxy)nitride phosphors by single-particle-diagnosis approach and time-resolved spectroscopy (2022)
  • Author(s): 許 健, 舟橋 司朗, 中西 貴之, 高橋 向星, 広崎 尚登, 武田 隆史
  • Organizer: セラミックス協会第35回秋季シンポジウム
• [Presentation] Insights into Multi-Band Emission of Inorganic (Persistent) Phosphors by Time-Resolved Spectroscopy (2022)
  • Author(s): 許 健, 中西 貴之, 高橋 向星, 広崎 尚登, 武田 隆史
  • Organizer: 日本応用物理学会極限的励起状態の形成と量子エネルギー変換研究グループ 第7回研究会
• [Presentation] Saturation mechanism of Ce3+/Eu2+ doped LED phosphors under high-power excitation (2022)
  • Author(s): Jian Xu, Kohsei Takahashi, Takayuki Nakanishi, Naoto Hirosaki, Takashi Takeda
  • Organizer: 日本セラミックス協会2022年年会
• [Presentation] Revisiting the Eu2+ emission in CaAlSiN3 (CASN) red phosphor by time-resolved spectroscopy (2022)
  • Author(s): Jian Xu, Kohsei Takahashi, Takayuki Nakanishi, Naoto Hirosaki, Takashi Takeda
  • Organizer: 第69回応用物理学会春季学術講演会
• [Presentation] New insights into the saturation mechanism of Ce3+/Eu2+ doped LED phosphors under high-power laser excitation (2022)
  • Author(s): Jian Xu, Kohsei Takahashi, Takayuki Nakanishi, Naoto Hirosaki, Takashi Takeda
  • Organizer: 第38回希土類討論会
• [Presentation] Low temperature time-resolved spectroscopy of the multi-site emission in SrAl2O4:Eu2+-Dy3+ (2021)
  • Author(s): Jian Xu, Kohsei Takahashi, Takayuki Nakanishi, Takashi Takeda, Naoto Hirosaki
  • Organizer: 第37回希土類討論会
• [Presentation] Insights into the multi-site emission from SrAl2O4:Eu2+-Dy3+ persistent phosphors by time-resolved streak imaging (2021)
  • Author(s): Jian Xu, Kohsei Takahashi, Takayuki Nakanishi, Takashi Takeda, Naoto Hirosaki
  • Organizer: 第68回応用物理学会春季学術講演会
• [Presentation] Insights Into the Saturation Mechanism of LED Phosphors (2021)
  • Author(s): Jian Xu, Kohsei Takahashi, Takayuki Nakanishi, Takashi Takeda, Naoto Hirosaki
  • Organizer: 第82回応用物理学会秋季学術講演会
• [Presentation] Revisiting the Multi-site Emission from SrAl2O4:Eu2+-Dy3+ by Time-resolved Spectroscopy (2021)
  • Author(s): Jian Xu, Kohsei Takahashi, Takayuki Nakanishi, Takashi Takeda, Naoto Hirosaki
  • Organizer: 日本セラミックス協会 第34回秋季シンポジウム
• [Book] Phosphor Handbook (3rd edition) (Chapter 11: Near-Infrared Phosphors with Persistent Luminescence over 1000 nm for Optical Imaging) (2022)
  • Author(s): Jian Xu, Michele Back, Setsuhisa Tanabe
  • Total Pages: 56
  • Publisher: CRC Press
  • ISBN: 9780367555085
• [Book] Processing of Ceramics: Breakthroughs in Optical Materials (Chapter 5: Solid-State Lighting) (2021)
  • Author(s): Jian Xu, Xin Liu, Jiang Li
  • Total Pages: 87
  • Publisher: Wiley Blackwell
  • ISBN: 9781119538707
• [Remarks] ResearcherID
  • URL: https://www.webofscience.com/wos/author/record/C-2984-2017
• [Remarks] ORCID
  • URL: https://orcid.org/0000-0002-1040-5090
• [Remarks] Google scholar
  • URL: https://scholar.google.com/citations?user=0knoBVAAAAAJ&hl=zh-CN
• [Remarks] SAMURAI(NIMS)
  • URL: https://samurai.nims.go.jp/profiles/xu_jian?locale=ja
• [Remarks] Publons
  • URL: https://publons.com/researcher/1436045/jian-xu/