(Lu_(0.99-x)Y_(x)Bi_(0.01))_(2)WO_(6)宽带绿色荧光粉的制备、性能调控及其在高显色指数白光LED中的应用

Preparation and properties regulation of(Lu_(0.99-x)Y_(x)Bi_(0.01))_(2)WO_(6) broadband green phosphors and their application in high color rendering index white light LEDs

高质量宽带绿色荧光粉是克服荧光粉转换白光LED(pc-wLED)“青光鸿沟”问题,实现高质量固态照明的关键.通过普适的固相法制备出尺寸均匀分散性良好的(Lu_(0.99-x)Y_(x)Bi_(0.01))_(2)WO_(6)宽带绿色荧光粉.采用共掺杂Y^(3+)的策略对系列荧光粉的物相、形貌及发光性能进行调控,并采用X-射线衍射、Rietveld精修、场发射扫描电子显微镜及光致发光等检测手段对所得样品进行了系统的研究.研究表明(Lu_(0.99-x)Y_(x)Bi_(0.01))_(2)WO_(6)荧光粉呈现宽带激发,激发范围覆盖200~400 nm波长区域,与商用紫外LED对应良好.在346 nm波长激发下,(Lu_(0.99-x)Y_(x)Bi_(0.01))_(2)WO_(6)荧光粉在400~800 nm范围内呈现出宽带绿光发射,半峰宽(FWHM)可达135 nm,最强峰值约为510 nm,对应于Bi^(3+)的^(3)P_(1)→^(1)S_(0)跃迁.Y^(3+)掺杂可显著提高(Lu_(0.99-x)Y_(x)Bi_(0.01))_(2)WO_(6)样品的结晶性及发光强度.采用所得的(Lu_(0.94)Y_(0.05)Bi_(0.01))_(2)WO_(6)与商用CaAlSiN3∶Eu^(2+)红色荧光粉、BaMgAl_(10)O_(17)∶Eu^(2+)蓝色荧光粉及365 nm紫外芯片制作出具有较高的显色指数(R_(a)=96,R_(9)=94),较低的相关色温(CCT=3846 K)高性能暖白光LED器件.

The development of high quality broadband green phosphor is the key to overcome“cyan gap”issue of phosphors conversion white LED(pc-wLED)and achieve high quality solid state lighting.Herein,a novel(Lu_(0.99-x)Y_(x)Bi_(0.01))_(2)WO_(6)broadband green phosphors with uniform size and good dispersion were prepared by high-temperature solid state method.The phase,morphology and luminescence properties of the phosphors were regulated by the strategy of co-doping Y^(3+),and the resulting samples were systematically investigated by X-ray diffraction,Rietveld structure refinement,field emission scanning electron microscopy and photoluminescence.The(Lu_(0.99-x)Y_(x)Bi_(0.01))_(2)WO_(6)phosphor shows broadband excitation,and the excitation range covers the wavelength region of 200~400 nm,which can correspond well with commercial UV LEDs.Under the excitation of 346 nm,the(Lu_(0.99-x)Y_(x)Bi_(0.01))_(2)WO_(6)phosphor shows broadband green emission in the range of 400~800 nm,with the full width at half maxima(FWHM)up to 135 nm and the most intense peak at about 510 nm,which corresponds to the^(3)P_(1)→^(1)S_(0)transition of Bi^(3+).Y^(3+)doping significantly improved the crystallinity and luminescence intensity of the(Lu_(0.99-x)Y_(x)Bi_(0.01))_(2)WO_(6)samples.The obtained(Lu_(0.94)Y_(0.05)Bi_(0.01))_(2)WO_(6)broadband green phosphor was mixed with commercial CaAlSiN 3∶Eu^(2+)red phosphor and BaMgAl_(10)O_(17)∶Eu^(2+)blue phosphor,and combined with the 365 nm UV chip to fabricate high-performance warm white LED devices,which have high color rendering index(R_(a)=96,R_(9)=94)and low correlated color temperature(CCT=3846 K).