Eu2+-actived oxyfluoride glass with highly efficient blue-cyan luminescence for X-ray imaging and white LED applications

Luminescent materials are crucial for diverse applications and require high efficiency and low cost. Eu²⁺-doped rare earth glasses attract interest due to structural stability, compositional tunability, and shape flexibility. Besides, Eu²⁺ ion processes the advantages of adjustable luminescent color, short decay time, and non-toxicity. These properties make Eu²⁺-doped glass promising for X-ray scintillators and white LED. However, the disordered glass structure creates defects acting as quenching centers, significantly limiting luminescence efficiency and posing a major challenge for achieving bright emission.

Recently, a team of material scientists led by Hai Guo from Zhejiang Normal University, China first reported the Eu²⁺-doped glass with excellent X-ray excited luminescence (XEL) and efficient blue-cyan photoluminescence. This work provides new insights into enhancing the scintillating and photoluminescent performance of glass.

The team published their work in Journal of Advanced Ceramics on March 19, 2026.

“In this work, four strategies, including selecting oxyfluoride glass as host, regulating optical basicity, introducing appropriate heavy elements, and adding carbon powders as reducing agent, were proposed to improve XEL and photoluminescent efficiency of Eu²⁺-doped glass,” said Hai Guo, professor at Department of physics at Zhejiang Normal University (China), a senior expert whose research interests focus on the field of glass.

“Surprisingly, Eu²⁺-doped glass exhibits excellent XEL intensity and bright blue-cyan photoluminescence,” said Hai Guo.

The XEL intensity of optimal glass reaches 308% of that of commercial Bi₄Ge₃O₁₂, which is a record-breaking value among Eu²⁺-doped glass scintillators. Besides, optimal glass exhibits high transmittance (>80% at 472 nm), linear response to X-ray dose, low detection limit (6.0 mGyair/s), excellent radiation stability, and X-ray absorption capacity. In the application of X-ray imaging, the imaging resolution of Eu²⁺-doped glass scintillator reaches 24 lp/mm. “The excellent XEL intensity and high transmittance jointly ensure high X-ray imaging quality,” said Hai Guo.

For photoluminescent performance, optimal glass shows high absorption efficiency of 89.3%, external quantum efficiency of 71.2%, and thermal stability (photoluminescent intensity at 423 K is 57.7% of that at room temperature). When combined with the 400 nm chip, the color rendering index of obtained white LED reaches 91.8. “The bright blue-cyan emission of Eu²⁺-doped glass effectively fills cyan gap and improves color rendering index of white LED,” said Hai Guo.

Other contributors include Junyu Chen, Yuheng Mei, Huihui Lin, and Lianjie Li from Department of physics at Zhejiang Normal University (China).

This work was supported by the National Natural Science Foundation of China (Grant No. 12574443).

About Author

Guo Hai, a professor at the Department of Physics, Zhejiang Normal University, mainly focuses on the research of new rare earth optical functional materials. He has published over 200 SCI-indexed papers as the first author or corresponding author in prestigious journals such as Adv. Mater., Adv. Funct. Mater., J. Adv. Ceram., Laser Photonics Rev., Sci. China Mater., Adv. Opt. Mater., J. Eur. Ceram. Soc., Chem. Eng. J., Sens. Actuators B Chem., Ceram. Int., Opt. Lett., and Opt. Express, with over 9815 citations and an H-index of 54. He has been listed on the "Global Top 2% Scientists List" for both career and annual rankings (2019-2025). He has led three National Natural Science Foundation projects and three provincial fund projects (including one provincial key project). He has won one Third prize of the Zhejiang Provincial Natural Science Award (ranked first) and one Third prize of the Chongqing Natural Science Award (ranked second). Since 2015, he has served as an Associate Editor for the internationally renowned ceramic journal J. Am. Ceram. Soc. He is also a Young Editor for Journal of Rare Earths (both Chinese and English editions) and Chinese Journal of Luminescence, and a member of the Luminescence Professional Committee of the Chinese Society of Rare Earths, the Optoelectronic Materials and Devices Professional Committee of the Chinese Society of Rare Earths, and the Council of the Special Glass Branch of the Chinese Ceramic Society. He published the translated work An Introduction to the Optical Spectroscopy of Inorganic Solid.

About Journal of Advanced Ceramics

Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen. JAC’s 2024 IF is 16.6, ranking in Top 1 (1/34, Q1) among all journals in “Materials Science, Ceramics” category, and its 2024 CiteScore is 25.9 (5/130) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508