摘要
近红外荧光转换发光二极管(pc-LED)在成像和检测领域的快速发展突显了对近红外二区(NIR-Ⅱ区)发光材料的迫切需求。然而,商用紫外LED芯片激发的高效NIR-Ⅱ荧光材料匮乏,制约了近红外光谱技术的应用。本文通过高温固相法成功制备了MgAl_(x)Ga_(2-x)O_(4)∶Ni^(2+)荧光材料,该材料的激发波长为390 nm,发射峰位于1300 nm,覆盖了NIR-Ⅱ区域。半高宽约为220 nm的超宽带NIR发射是由于Ni^(2+)处于一个弱晶体场环境中,这种环境是由于MgAl_(x)Ga_(2-x)O_(4)基体中[(Al/Ga)O_(6)]八面体中心周围的高电荷极化导致的空间不对称畸变造成的。通过改变体系中Al^(3+)与Ga^(3+)的离子比例,将NIR-Ⅱ区的发射强度大大提高,发光强度提升为原来的9倍左右。着重研究了Ni^(2+)掺杂最优比例MgAl_(1.5)Ga_(0.5)O_(4)的光谱特性。探讨了体系的温度特性,使用掺Ni^(2+)的近红外荧光粉和商业高效紫外LED芯片(@395 nm)构建了NIR pc-LED,研究表明该材料体系可能在pc-LED光谱技术中展现出较大潜力。这种阳离子调制策略将给近红外发光材料的性能提升提供有效的方法。
Near-infrared(NIR)-Ⅱphosphors converted light-emitting diodes(NIR pc-LEDs)are ideal NIR sourc⁃es for versatile applications.There is an urgent requirement to explore the NIR-Ⅱluminescent materials.Herein,we have successfully synthesized MgAl_(x)Ga_(2-x)O_(4)phosphor materials via a high-temperature solid-state method.The Ni^(2+)activated MgAl_(x)Ga_(2-x)O_(4)exhibits an excitation wavelength of 390 nm and an emission peak at 1300 nm,covering the NIR-Ⅱregion.This ultra-broadband emission is due to Ni^(²⁺)in a weak crystal field environment,which caused by spatially asymmetric distortions from high-charge polarization around the[(Al/Ga)O_(6)]octahedral centers.A sim⁃ple cation modulation strategy(Al/Ga)is proposed to successfully largely enhance the NIR-emission intensity 9 times as much as before.An optimized Al/Ga ratio in MgAl_(x)Ga_(2-x)O_(4)system and the corresponding thermal stability were studied.Further,a NIR pc-LED is fabricated by employing MgAl1.5Ga0.5O4∶Ni^(2+)coating on a 395 nm LED chip,showcasing its promising application prospects in NIR pc-LED.
作者
杨宜晨
吕伟
康晓娇
YANG Yichen;LYU Wei;KANG Xiaojiao(School of Electrical Engineering and Intelligentization,Dongguan University of Technology,Dongguan 523808,China;Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices,School of Information and Optoelectronic Science and Engineering,South China Normal University,Guangzhou 510006,China)
出处
《发光学报》
EI
CAS
CSCD
北大核心
2024年第11期1839-1848,共10页
Chinese Journal of Luminescence
基金
广东省基础与应用基础研究基金(2022A1515140064)
东莞市社会发展科技项目(20221800905152)。
