发射峰为875 nm的高热稳定性立方相Sc(PO_(3))_(3):Cr^(3+)荧光粉

A highly thermal stable cubic-phase Sc(PO_(3))_(3):Cr^(3+) phosphor with emitting peak at 875 nm

近红外(NIR)荧光粉转换型发光二极管(pc-LED)具有尺寸小、效率高以及光谱易于调节的特点,在特种照明、传感、微型近红外光谱仪等各领域有很好的应用前景.目前,已报道的发射波长超过850 nm的近红外荧光粉的荧光热稳定性较差.在本项研究中,我们合成了一种立方相结构的Sc(PO_(3))_(3):xCr^(3+)(x=0,1,5,10,12,14,16,18 at%)荧光粉,其具有725–1150 nm的宽发射带,发射峰为875 nm,与之前报道的发射峰超过850 nm的荧光粉相比,其表现出优异的热稳定性,在423 K下,5 at%样品的积分发光强度保留了室温下的73.4%.通过对比研究立方相和单斜相Sc(PO_(3))_(3):Cr^(3+)荧光粉变温X射线衍射,发现立方相荧光粉优异的荧光热稳定性可能归因于高温下较小的键长和键角变化.利用该荧光粉制备的NIR pc-LED在150 mA电流驱动下,产生了26.62 mW的NIR辐射功率.驱动电流为10 mA时,最高电光转换效率为11.87%.这项工作为开发具有优异荧光热稳定性的Cr^(3+)离子掺杂近红外荧光粉提供了思路.

The compact size and high efficiency of nearinfrared(NIR) phosphor-converted light-emitting diodes(pcLEDs) make them promising light sources in various fields,such as miniature NIR spectrometer. However, the current state of NIR phosphors with emission wavelengths exceeding850 nm shows poor photoluminescence(PL) thermal stability.In this work, we present cubic-phase Sc(PO_(3))_(3):xCr^(3+)(x = 0, 1,5, 10, 12, 14, 16 and 18 at%) phosphors that exhibit broadband emission ranging from 725 to 1150 nm, with a peak at 875 nm.Particularly, the PL intensity of the 5 at% sample retains 73.4%of its value at room temperature when measured at 423 K,exhibiting exceptional thermal stability compared with previously reported phosphors with emission peaks exceeding850 nm. Through a comparison investigation on the variabletemperature X-ray diffraction patterns of cubic-and monoclinic-phase Sc(PO_(3))_(3):Cr^(3+) phosphors, it was revealed that achieving good PL thermal stability in the cubic-phase phosphor may be attributed to the minimal bond length and bond angle variations at elevated temperatures. The fabricated NIR pc-LEDs, driven with a 150-mA current, produce an NIR radiant flux of 26.62 mW. The highest electro-optical conversion efficiency is 11.87% under a drive current of 10 mA. This work provides insights for the discovery of Cr^(3+)ion-doped NIR phosphors with excellent PL thermal stability.