宽带近红外氟化物荧光粉Cs_(2)NaAlF_(6):Cr^(3+)的制备与发光特性研究

Preparation and Luminescent Properties Research of Broadband Near-Infrared Fluoride Phosphor Cs_(2)NaAlF_(6):Cr^(3+)

荧光粉转化发光二极管(pc-LEDs)在近红外光谱技术和近红外成像技术领域中有着重要的应用前景,但是开发新型的宽带近红外荧光粉仍然是一个挑战。采用铵盐转化的方法制备了一系列六方相结构的Cs_(2)NaAlF_(6)∶Cr^(3+)近红外荧光粉,在434 nm蓝光激发下,样品能够产生峰值约为780 nm、半峰全宽为106 nm的宽带近红外光,并且在150℃时发光强度为室温(25℃)时的68.4%。进一步地,将Cs_(2)NaAlF_(6)∶0.30Cr^(3+)荧光粉和蓝光LED芯片封装成宽带近红外pc-LED器件,在驱动电流为1000 mA时,其近红外光输出功率为226.49 mW,相应的能量转换效率为2.4%,该器件有望在静脉成像等领域中获得应用。

Phosphor-converted light-emitting diodes(pc-LEDs) have great potential in near-infrared spectroscopy technology and near-infrared imaging technology. However, the development of novel broadband near-infrared phosphors remains a challenge. In this paper, a series of hexagonal phase structure Cs_(2)NaAlF_(6)∶Cr^(3+) near-infrared emission phosphors are prepared by an ammonium salt conversion method. Under 434 nm blue light excitation, the phosphors show a broadband near-infrared emission band peak at ~780 nm with full width at half maximum of 106 nm, and the luminescence intensity at 150 ℃ can maintain 68. 4% of that at room temperature(25 ℃). Further, a broadband near-infrared pc-LED device is fabricated based on Cs_(2)NaAlF_(6)∶0. 30 Cr^(3+) phosphor and a blue LED chip. When the driving current is 1000 mA, a near-infrared output power of 226. 49 mW is obtained in pc-LED device, and the corresponding energy conversion efficiency is 2. 4%. The device may find application in veins imaging and other fields.