Cyan-Emitting Sialon-Polytypoid Phosphor Discovered by a Single-Particle-Diagnosis Approach
Cyan-Emitting Sialon-Polytypoid Phosphor Discovered by a Single-Particle-Diagnosis Approach
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通过单粒子诊断方法发现青色发射赛隆多型荧光粉
DOI：
10.1149/2162-8777/ac331c
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发表时间：
2021
影响因子：
2.2
通讯作者：
Takashi Takeda
中科院分区：
文献类型：
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作者：
Jian Xu;Shiro Funahashi;Kohsei Takahashi;Takayuki Nakanishi;Naoto Hirosaki;Takashi Takeda
利用基于单晶X射线衍射和单粒子光谱的荧光粉筛选新方法，即单粒子诊断法，发现了一种新的Eu 2+激活的氮氧化物发氰荧光粉（Si2.5Al9.5O0.5N12.5：Eu 2+）。该颗粒的单晶X射线衍射分析表明，该赛隆多型体在Cmcm空间群（No.63）中结晶，其中a= 3.0704 μ m，B= 18.6697 μ m，c= 35.7178 μ m，Z= 8。正交相结构是由[MX 4]（M= Si，Al; X= O，N）四面体连接而成的高度凝聚网络结构。虽然基质中没有明显的晶位可以容纳较大的Eu 2+离子，但单晶颗粒的时间分辨条纹成像表明，在氮氧化物中，峰值为~ 500 nm，半高宽（FWHM）为~ 61 nm的青色发光带具有典型的Eu 2+荧光寿命（~ 0.39 μs）。此外，Eu 2+发射带的短波长区（450-500 nm）和长波长区（500- 550 nm）之间存在微小的寿命变化（0.32 μs vs 0.47 μs），这可能表明Eu 2+周围存在两种不同的结晶环境。这种在365 nm处具有高效激发性的赛隆-多型体发氰磷光体可以在近紫外（NUV）激发的wLED中作为全无机颜色转换器找到其潜在的应用。
Benefiting from a novel phosphor screening method based on single crystal X-ray diffractometry and single-particle spectroscopy, ie, the single-particle-diagnosis approach, a new Eu 2+-activated cyan-emitting oxynitride phosphor (Si 2.5 Al 9.5 O 0.5 N 12.5: Eu 2+) was discovered. Single crystal X-ray diffraction analysis of the particle revealed that this sialon-polytypoid crystallizes in the Cmcm space group (No. 63) with a= 3.0704 Å, b= 18.6697 Å, c= 35.7178 Å, and Z= 8. The analyzed orthorhombic structure is built up of highly condensed networks that constructed from linked [MX 4](M= Si, Al; X= O, N) tetrahedra. Although there are no obvious crystalline sites able to accommodate larger Eu 2+ ions in the host, the time-resolved streak imaging of a single crystalline particle indicates that the cyan-emitting band peaking at∼ 500 nm with a relatively narrow full-width at half-maximum (FWHM) of∼ 61 nm exhibits a typical Eu 2+ fluorescent lifetime (∼ 0.39 μs) in oxynitrides. Besides, slight lifetime variation (0.32 μs vs 0.47 μs) between shorter wavelength region (450–500 nm) and longer wavelength region (500–550 nm) of the Eu 2+ emission band may suggest two different crystalline environments around Eu 2+. This sialon-polytypoid cyan-emitting phosphor with efficient excitability at 365 nm may find its potential application as an all-inorganic color-converter in near-ultraviolet (NUV) excited wLEDs.