Tsai Yi-Ting, Chen Pei-Xuan, Kamiński Mikołaj, Majewska Natalia, Mahlik Sebastian, Fang Mu-Huai
Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan.
Institute of Organic and Polymeric Materials, National Taipei University of Technology, Taipei 10608, Taiwan.
ACS Appl Opt Mater. 2024 Mar 1;2(12):2401-2408. doi: 10.1021/acsaom.3c00464. eCollection 2024 Dec 27.
Short-wave infrared (SWIR) phosphor-converted light-emitting diode (LED) technology holds promise for advancing broadband light sources. Despite the potential, limited research has delved into the energy transfer mechanism from sharp-line to broadband emission in SWIR phosphors, which remains underexplored. Herein, we demonstrate bright SWIR phosphors achieved through Cr/Ni energy transfer in LiGaAl O. High-resolution X-ray diffraction revealed the typical solid solution and distortion occurring in Al octahedral sites. In addition, the X-ray absorption spectrum illustrates that Cr and Ni have different coordination environments, showing the possibility that they occupy different positions or that the coordinated environment of Ni is distorted due to charge imbalance. Temperature-dependent studies provide insights into the energy transfer dynamics between Cr/Ni, from the E level of Cr (sharp band) to the T level of Ni (broadband). The increased emission intensity at lower temperatures in the = 0.6 and = 1.0 samples can be explained by the positioning of the T level above the E level of Cr ions. Finally, we established a mechanism involving a sharp line to broadband energy transfer showcasing a high-power SWIR LED with a radiant power of 21.45 mW.
短波红外（SWIR）磷光转换发光二极管（LED）技术有望推动宽带光源的发展。尽管具有潜力，但针对SWIR磷光体中从锐线发射到宽带发射的能量转移机制的研究有限，仍有待深入探索。在此，我们展示了通过LiGaAlO中Cr/Ni能量转移实现的明亮SWIR磷光体。高分辨率X射线衍射揭示了在Al八面体位点出现的典型固溶体和畸变。此外，X射线吸收光谱表明Cr和Ni具有不同的配位环境，这表明它们可能占据不同位置，或者由于电荷不平衡导致Ni的配位环境发生畸变。温度相关研究深入了解了Cr/Ni之间的能量转移动力学，即从Cr的E能级（锐带）到Ni的T能级（宽带）。在λ = 0.6和λ = 1.0样品中，较低温度下发射强度增加可通过T能级位于Cr离子E能级之上得到解释。最后，我们建立了一种涉及锐线到宽带能量转移的机制，展示了一款辐射功率为21.45 mW的高功率SWIR LED。
