Synthesis of Eu2+/Eu3+ Co-Doped Gallium oxide nanocrystals as a full colour converter for white light emitting diodes.
Synthesis of Eu2+/Eu3+ Co-Doped Gallium oxide nanocrystals as a full colour converter for white light emitting diodes.
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DOI：
10.1016/j.jcis.2018.06.047
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发表时间：
2018-11
影响因子：
9.9
通讯作者：
Caiyan Yu;Mengmeng Cao;D. Yan;Sunqi Lou;Chaochao Xia;T. Xuan;R. Xie;Huili Li
中科院分区：
文献类型：
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作者：
Caiyan Yu;Mengmeng Cao;D. Yan;Sunqi Lou;Chaochao Xia;T. Xuan;R. Xie;Huili Li
在300 °C的低反应温度下，在有机相中合成了Eu2+和Eu3+共掺杂的Ga2O3纳米晶（Ga2O3:Eu NCs）。采用油胺（OAm）和乙酰丙酮（acac）钝化Ga2O3:Eu NCs表面。Eu2+和Eu3+的共存以及acac和OAm的钝化作用使ga2o3在200-500 nm的宽光谱范围内被激发。吸收带加宽的原因是强acac → Ln（III）配体在~ 370 nm处发生了金属电荷转移跃迁，Eu(III) f-f在395 nm处发生了7f0→5l6跃迁，在465 nm处发生了7f0→5d2跃迁，以及Eu(II) 4f → 5d在~ 400 nm处发生了有效的电子跃迁。在近紫外激发下，将Eu（III）的f-f电子跃迁产生的橙红色光与ga2o3氧缺陷能级产生的蓝绿黄光相结合，可以实现白光发射。此外，将优化后的量子产率为14.5%的Ga2O3:Eu NCs涂覆在395 nm的近紫外芯片上，制成白光发光二极管。其发光效率为34 lm/W， CIE色坐标为（0.2964,0.2831），显色指数为80。
Eu2+and Eu3+co-doped Ga2O3nanocrystals (Ga2O3:Eu NCs) were synthesized in an organic phase at a low reaction temperature of 300 °C. The surface of Ga2O3:Eu NCs was passivated by oleylamine (OAm) and acetylacetone (acac). The coexistence of Eu2+and Eu3+as well as passivation by acac and OAm enable Ga2O3to be excited in the broad spectral range of 200–500 nm. The broadened absorption band is attributed to the strong acac → Ln(III) ligand to the metal charge transfer transition at ∼370 nm, Eu(III) f-f allowed7F0→5L6transition at 395 nm, and7F0→5D2transition at 465 nm, as well as the efficient electronic transition of Eu(II) 4f → 5d at ∼400 nm. Under near-ultraviolet excitation, white light emission can be achieved by combining orange-red light from f-f electronic transition of Eu(III) with blue-green-yellow light from Ga2O3oxygen defects levels. Furthermore, the resultant Ga2O3:Eu NCs with optimized quantum yield of 14.5% were coated onto 395 nm near-ultraviolet chips to fabricate a white light emitting diode. It exhibits a luminous efficiency of 34 lm/W, CIE colour coordinate of (0.2964, 0.2831) and high colour rendering index of 80.