Dang Peipei, Liu Dongjie, Wei Yi, Li Guogang, Lian Hongzhou, Shang Mengmeng, Lin Jun
State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
University of Science and Technology of China, Hefei, 230026, People's Republic of China.
Inorg Chem. 2020 May 4;59(9):6026-6038. doi: 10.1021/acs.inorgchem.0c00015. Epub 2020 Apr 10.
Phosphor-converted white-light-emitting diodes (pc-WLEDs) rely on combining a near-ultraviolet (n-UV) or blue chip with trichromatic and yellow-emitting phosphors. It is challenging to discover cyan-green-emitting (480-520 nm) phosphors for compensating the spectral gap and producing full-spectrum white light. In this work, we successfully discovered two unprecedented bright cyan-green emitting RbRVO (R = Y, Lu) phosphors that gives emission bands centered at 500 nm upon 362 nm n-UV light excitation. Interestingly, the both self-activated compounds exhibit high internal quantum efficiencies (IQEs) of 71% for RbYVO and 85% for RbLuVO, respectively. Moreover, controllable emission color can be successfully tuned from cyan-green to orange-red across the warm white light region by design strategy of VO → Eu energy transfer. The thermal quenching of as-prepared phosphors could be effectively mitigated by this design strategy. Finally, the as-fabricated n-UV (λ = 370 nm) pumped phosphor-converted (pc) W-LED devices utilizing RbRVO (R = Y, Lu) along with commercial phosphors demonstrate well-distributed warm white light with high color-rendering index (CRI) of 91.9 and 93.5, and a low correlated color temperature (CCT) of 5095 and 4946 K. It suggests that the both vanadate phosphors have potential applications in full-spectrum pc-WLEDs.
磷光转换白光发光二极管（pc-WLED）依靠将近紫外（n-UV）或蓝色芯片与三色和发黄光的磷光体相结合。发现用于补偿光谱间隙并产生全光谱白光的蓝绿色发光（480-520nm）磷光体具有挑战性。在这项工作中，我们成功发现了两种前所未有的明亮蓝绿色发光的RbRVO（R = Y，Lu）磷光体，在362nm n-UV光激发下发射带中心位于500nm。有趣的是，这两种自激活化合物分别表现出71%（RbYVO）和85%（RbLuVO）的高内量子效率（IQE）。此外，通过VO→Eu能量转移的设计策略，可以在整个暖白光区域成功地将发射颜色从蓝绿色调节到橙红色。通过这种设计策略可以有效减轻所制备磷光体的热猝灭。最后，利用RbRVO（R = Y，Lu）以及商用磷光体制备的n-UV（λ = 370nm）泵浦磷光转换（pc）W-LED器件展示了分布均匀的暖白光，显色指数（CRI）分别为91.9和93.5，相关色温（CCT）分别为5095和4946K。这表明这两种钒酸盐磷光体在全光谱pc-WLED中具有潜在应用。
