[Zn-Ge] co-substitutes [Ga-Ga] to coordinately broaden the near-infrared emission of Cr in GaO phosphors

• Published in: Physical chemistry chemical physics : PCCP Vol. 25; no. 3; pp. 29 - 297
• Main Authors: Lin, Jianhua, Zhou, Liuyan, Shen, Yuyu, Fu, Jie, Chen, Yanling, Lei, Lei, Ye, Renguang, Shen, Yang, Deng, Degang, Xu, Shiqing
• Format: Journal Article
• Published: 18.01.2023
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d2cp04737c

Here, a "chemical unit co-substitution" method is used to improve the near-infrared (NIR) emission of phosphors, using [Zn 2+ -Ge 4+ ] to co-substitute [Ga 3+ -Ga 3+ ] sites to reduce crystal field splitting to affect the structure of gallium oxide. A series of broadband NIR phosphors are synthesized by a high-temperature solid-phase method, and their phase structures, crystal structures, morphologies, diffuse reflectance spectra, and luminescence lifetimes are investigated. The Ga 1.68 (Zn-Ge) 0.3 O 3 :0.02Cr 3+ (GZGOC) phosphor exhibits NIR wide-band emission, with a peak wavelength of 766 nm and a half-width of 138 nm. Meanwhile, the quantum yield of photoluminescence can reach 81.2%. The phosphor has good thermal stability. When the temperature reaches 373 K, its emission intensity still remains at 73.4% of that at room temperature. A 460 nm LED chip and this phosphor are used to fabricate a phosphor-converted light emitting diode (pc-LED) device which can be used as a NIR light source. All these results show the application potential of the as-prepared phosphor in NIR imaging. This paper focuses on the use of [Zn 2+ -Ge 4+ ] to co-replace [Ga 3+ -Ga 3+ ], which redshifts the near-infrared emission of Cr 3+ in Ga 2 O 3 , and broadens the full width at half maximum.