Suppressing Self‐Oxidation of Eu2+ in Li2CaSiO4 for Full‐Spectrum Lighting and Accurate Temperature Sensing

• Published in: Laser & photonics reviews 2024-10, Vol.18 (10), p.n/a
• Main Authors: Ding, Yang, Lu, Xinyue, Maitra, Soumyajit, Wang, Yan, Pei, Lang, Mao, Qinan, Liu, Meijiao, Zhong, Jiasong, Chen, Daqin
• Format: Article
• Language: English
• Subjects: Color temperature; cyan‐light, Eu2+ doped phosphors; Decay rate; Emission; Europium; Luminous intensity; Oxidation; Phosphors; Quantum efficiency; self‐oxidation; temperature sensing; Thermal stability; WLED
• ISSN: 1863-8880; 1863-8899
• DOI: 10.1002/lpor.202400296

Eu2+‐doped phosphors have attracted the great attention of researchers in the past decade. However, Eu2+ dopant in inorganic hosts often suffers from the self‐oxidation effect, therefore causing the attenuated emission intensity and quantum efficiency. In this regard, developing Eu2+ doped phosphors with the prohibited self‐oxidation effect of Eu2+ and increased thermal stability is urgently required. Herein, an innovative cyan‐light emitting Li2CaSiO4:Eu2+/Eu3+, Lu3+ (LCSO) phosphor is designed. Both experimental results and theoretical calculations demonstrate that adding Lu3+ restricts the self‐oxidation of Eu2+ into Eu3+, thus improving the emission of Eu2+. Meanwhile, the Lu3+ introduction brings out excellent thermal stability. Finally, an efficient WLED with a color temperature (CCT) of 4573 K and a high color rendering index (Ra) of 84.2 is obtained using the as‐prepared phosphor due to the perfect compensation of the cyan light. As the introduction of Lu3+ improves the stability of Eu2+, a much greater difference in PL decay rate between Eu2+ and Eu3+ in LCSO is reached, thereby improving their sensitivity in temperature sensing. The strategy of Lu3+ introduction for prohibiting the self‐oxidation of Eu2+ for efficient and stable Eu2+ emission may stimulate some new ideas in designing high‐performance phosphors for more diverse applications. The introduction of Lu3+ drastically improves the cyan light emission of Li2CaSiO4: Eu2+ phosphor owing to the suppressed self‐oxidation of Eu2+. The developed phosphor can be applied in a full‐spectrum white light‐emitting diode with a color correlated temperature of 4573 K and a high color rendering index of 84.2.