Journal ArticleDOI
Protected-annealing regulated defects to improve optical properties and luminescence performance of Ce:YAG transparent ceramics for white LEDs
Sun Bingheng,Le Zhang,Le Zhang,Le Zhang,Tianyuan Zhou,Tianyuan Zhou,Shao Cen,Lei Zhang,Yuelong Ma,Yuelong Ma,Qing Yao,Qing Yao,Zhigang Jiang,Zhigang Jiang,Farida Selim,Hao Chen +15 more
TLDR
In this article, vacuum as-sintered high quality Ce:YAG ceramics were subjected to various annealing conditions, and their microstructural evolution, and optical and luminescence properties were monitored and studied systematically.Abstract:
Ce:YAG transparent ceramic, a promising photo-converter for white LED lighting, faces a significant obstacle of post-annealing treatments, which allow the simultaneous elimination of defections and the regulation of the redox state of Ce. In this paper, vacuum as-sintered high quality Ce:YAG ceramics were subjected to various annealing conditions, and their microstructural evolution, and optical and luminescence properties were monitored and studied systematically. The results showed that air annealing efficiently benefited the microstructure and optical transmittance. In addition, the absorption band below 300 nm was strongly dependent on the annealing strategies due to the elimination of defects (e.g. F/F+-type color centers) and charge transfer (CT) between Ce(III) and Ce(IV). By constructing with 1350 °C air annealed Ce:YAG ceramics, a high-performance white LED with a luminous efficiency radiation (LER) exceeding 220 lm W−1 was achieved, thanks to the “protected”-annealing condition, which guaranteed moderate CT from Ce(IV) to Ce(III) due to weakened pump light absorption by defects. Differing from traditional Ce:YAG phosphors, excrescent oxygen vacancies were introduced by annealing Ce:YAG ceramics in hydrogen, leading to deteriorated luminescence properties. Therefore, it is expected that this refined preparation of Ce:YAG photo-convertors could drive the development of white LED lighting.read more
Citations
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Journal ArticleDOI
YAG:Ce3+ Transparent Ceramic Phosphors Brighten the Next-Generation Laser-Driven Lighting
Qi Yao,Qi Yao,Pan Hu,Peng Sun,Min Liu,Rui Dong,Kefu Chao,Yongfu Liu,Jun Jiang,Haochuan Jiang +9 more
TL;DR: YAG:Ce3+ transparent ceramic phosphors (TCPs) are regarded as the most promising luminescent converter for laser-driven (LD) lighting as discussed by the authors.
Journal ArticleDOI
A high quantum efficiency CaAlSiN3:Eu2+ phosphor-in-glass with excellent optical performance for white light-emitting diodes and blue laser diodes
Yujie Zhang,Zelong Zhang,Xiaodong Liu,Guangzhan Shao,Linli Shen,Jianming Liu,Weidong Xiang,Xiaojuan Liang +7 more
TL;DR: In this article, a series of red-emitting phosphor-in-glass materials (R-PiGs) with different CASN:Eu2+ concentrations and sintering temperatures were successfully synthesized by dispersing the CASN eu 2+ phosphor into a B2O3-Na2O-SiO2-CaO glass matrix.
Journal ArticleDOI
Ultra-broadband cyan-to-orange emitting Ba1+xSr1−xGa4O8:Bi3+ phosphors: luminescence control and optical temperature sensing
Peipei Dang,Peipei Dang,Dongjie Liu,Dongjie Liu,Xiaohan Yun,Guogang Li,Dayu Huang,Hongzhou Lian,Mengmeng Shang,Jun Lin,Jun Lin,Jun Lin +11 more
TL;DR: In this paper, a series of Ba1+xSr1−xGa4O8:Bi3+ (x = 0-0.7) phosphors that exhibit extremely broadband emission, covering almost the entire visible region and extending to the deep red region, when excited by ultraviolet light.
Journal ArticleDOI
High recorded color rendering index in single Ce,(Pr,Mn):YAG transparent ceramics for high-power white LEDs/LDs
Yuelong Ma,Yuelong Ma,Le Zhang,Le Zhang,Le Zhang,Tianyuan Zhou,Sun Bingheng,Yun Wang,Kang Jian,Pan Gao,Jin Huang,Farida Selim,Ching-Ping Wong,Ming Li,Hao Chen +14 more
TL;DR: In this article, a single-structured Ce,(Pr,Mn):YAG TC with wide peak and narrow peak red light emissions was designed and fabricated via a solid-state reaction and a vacuum sintering method.
Journal ArticleDOI
A new CaF2-YAG:Ce composite phosphor ceramic for high-power and high-color-rendering WLEDs
Gu Chi,Xiao-Jun Wang,Chao Xia,Shuxing Li,Peng Liu,Dongzhen Li,Huili Li,Guohong Zhou,Jian Zhang,Rong-Jun Xie +9 more
TL;DR: In this paper, a new CaF2-YAG:Ce phosphor composite was proposed for high-power white light-emitting diodes (WLEDs).
References
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Mn2+ and Mn4+ red phosphors: synthesis, luminescence and applications in WLEDs. A review
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