A novel pale‐yellow Ba 2 ZnGe 2 O 7 :Bi 3+ phosphor with site‐selected excitation and small thermal quenching

• Published in: Journal of the American Ceramic Society 2019-10, Vol.102 (10), p.6068-6076
• Main Authors: Wu, Quansheng, Chen, Xi, Chen, Hande, Zhang, Hanqiang, Zhou, Jiangcong
• Format: Article
• Language: English
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.16477

A novel pale‐yellow Ba 2 ZnGe 2 O 7 :Bi 3+ phosphor with site‐selected excitation and small thermal quenching was synthesized by conventional solid‐state sintering. The crystal structure and luminescence properties have been investigated in detail for the first time using XRD patterns, photoluminescence spectra, diffuse reflection spectra, decay curves, and temperature‐dependent emission spectra. The results reveal that the excitation spectrum of Ba 2 ZnGe 2 O 7 :Bi 3+ phosphor locates in the near‐ultraviolet region of 300‐400 nm, and its emission shows an obvious site‐selective excitation phenomenon since Bi 3+ ions occupy two different crystallographic sites in the Ba 2 ZnGe 2 O 7 host. When excited under 360 nm, the phosphors show a pale‐yellow emission in the range of 400‐700 nm with the maximum peaking at 520 nm, while when excited under 316 nm, the phosphors show a blue emission in the range of 400‐700 nm with the maximum peaking at 480 nm. In addition, the emission of Ba 2 ZnGe 2 O 7 :Bi 3+ can also be easily controlled by changing the Bi 3+ concentration. The Ba 2 ZnGe 2 O 7 :Bi 3+ phosphor has small thermal quenching, and its emission intensity only decreases by 2% at 200°C. The results indicate that this novel pale‐yellow Ba 2 ZnGe 2 O 7 :Bi 3+ phosphor could be conducive to the development of white light‐emitting diodes.