“Two-pronged approach” unlocks material secret to cool laser lighting devices Northeastern University researchers slash operating temperatures and boost efficiency in high-power laser systems

Led by Professor Shaohong Liu, the researchers optimized LuAG:Ce fluorescent thin films—key components in laser lighting—by simultaneously enhancing crystallinity and increasing the concentration of Ce³⁺ ions, the film’s luminescent powerhouses. The results are striking: under high-power laser excitation (18 W/mm²), the films’ operating temperature dropped by nearly 100 °C, with further temperature reduction achieved via CO annealing. Impressively, the luminous efficiency increased by 73.2% under 13 W/mm² laser excitation. This dual breakthrough not only cools the system but also amplifies its glow, paving the way for practical, high-performance laser lighting.

“We’ve turned a classic trade-off into a win-win,” says Liu. “By fine-tuning the material itself, we’ve eliminated the need to sacrifice brightness for cooling—a game-changer for next-generation lighting technologies.”

Key Innovations and Results

Using a cost-effective spray pyrolysis method, the team deposited 22.17 μm-thick LuAG:Ce films onto sapphire substrates, a process ideal for large-scale production. They then employed two strategic steps:

1. Crystallinity Boost: Annealing the films in air at 1500 °C raised crystallinity from 75.5% to 87.4%, slashing the temperature by 95.6 °C under intense laser exposure. Higher crystallinity improved heat dissipation and light emission simultaneously.
2. Ce³⁺ Enhancement: A subsequent CO atmosphere anneal at 1500 °C increased Ce³⁺ content from 35.9% to 46.1%, cutting the temperature an additional 20 °C and boosting luminous efficiency by 73.2%.

The optimized films proved their mettle under a 13 W/mm² laser: temperatures stabilized at 140 °C within 30 seconds, and after 1800 seconds, they retained 87.1% of their initial luminous flux. This thermal and optical stability positions the material as a standout candidate for demanding applications.

Lighting the Future

“This isn’t just about keeping things cool—it’s about enabling technologies that demand both brilliance and reliability,” Liu explains. The team’s “material code” could illuminate everything from car headlights piercing the night to projectors vivid enough for daylight use. With its scalability and performance, this advance brings laser lighting closer to widespread adoption.

The study’s implications extend beyond illumination. By offering a blueprint for thermal management in advanced materials, it could inspire innovations in fields like medical imaging and high-power electronics.

About the Research

The team published their work in Journal of Advanced Ceramics on March 11, 2025.

Published in the Journal of Advanced Ceramics—a top-tier materials science journal with an impact factor of 18.6—the research was supported by the National Natural Science Foundation of China and the Yunnan Precious Metals Laboratory. Full details are available at DOI: 10.26599/JAC.2025.9221061 or on ResearchGate.

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 2023 IF is 18.6, ranking in Top 1 (1/31, Q1) among all journals in “Materials Science, Ceramics” category, and its 2023 CiteScore is 21.0 (top 5%) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508

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