Miao Shihai, Liang Yanjie, Chen Dongxun, Shi Ruiqi, Shan Xihui, Zhang Yi, Xie Fei, Wang Xiao-Jun
Key Laboratory for Liquid-Solid Structure Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan, Shandong250061, China.
Department of Physics, Georgia Southern University, Statesboro, Georgia30460, United States.
ACS Appl Mater Interfaces. 2022 Nov 30;14(47):53101-53110. doi: 10.1021/acsami.2c18388. Epub 2022 Nov 17.
Infrared-emitting phosphor-converted light-emitting diodes (LEDs) are desirable light sources for a very wide range of applications such as spectroscopy analysis, nondestructive monitoring, covert information identification, and night-vision surveillance. The most important aspect of infrared emitters for spectroscopy is to cover the widest possible wavelength range of emitted light. However, developing ultrabroad-band infrared emitters based on converter technology is still a challenging task due to the lack of suitable phosphor materials that emit in a wide wavelength range upon excitation from blue-emitting chips. Herein, this work demonstrates Cr-activated MgSiO infrared phosphors with a super wide infrared spectral range of 600 to 1400 nm and high internal quantum yield up to 80.4% upon 460 nm excitation. Site-selective occupancy of Cr emitters in two different Mg sites in the MgSiO lattice results in two distinct broad emission bands peaking at 760 and 970 nm, both of which contribute to the ultrabroad-band infrared luminescence with a full width at half maximum (FWHM) of 419 nm. This is by far the broadest infrared emission to the best of our knowledge. On this basis, an ultrabroad-band infrared LED prototype has been fabricated by the combination of the MgSiO:Cr phosphor with a blue LED chip, which shows great potential for imaging and sensing applications. This work demonstrates that site-selective occupancy control of Cr ions is an effective strategy for developing ultrabroad-band Cr-doped phosphors.
红外发射的磷光体转换发光二极管（LED）是适用于非常广泛应用的光源，如光谱分析、无损监测、隐蔽信息识别和夜视监视。用于光谱学的红外发射器最重要的方面是覆盖尽可能宽的发射光波长范围。然而，由于缺乏在蓝色发光芯片激发下能在宽波长范围内发光的合适磷光体材料，基于转换器技术开发超宽带红外发射器仍然是一项具有挑战性的任务。在此，这项工作展示了Cr激活的MgSiO红外磷光体，其在460nm激发下具有600至1400nm的超宽红外光谱范围和高达80.4%的高内量子产率。Cr发射体在MgSiO晶格中两个不同Mg位点的位点选择性占据导致两个不同的宽发射带，峰值分别在760和970nm，这两个发射带都有助于超宽带红外发光，半高宽（FWHM）为419nm。据我们所知，这是迄今为止最宽的红外发射。在此基础上，通过将MgSiO:Cr磷光体与蓝色LED芯片相结合，制备了一个超宽带红外LED原型，该原型在成像和传感应用中显示出巨大潜力。这项工作表明，Cr离子的位点选择性占据控制是开发超宽带Cr掺杂磷光体的有效策略。
