Tran Manh Trung, Quang Trung Do, Tri Tuan Nguyen, Tuan Nguyen Trong, Tu Nguyen, Van Du Nguyen, Duy Hung Nguyen, Van Quang Nguyen, Thi Hao Tam Tong, Trung Kien Nguyen Duc, Hieu Nguyen Minh, Huy Pham Thanh
Faculty of Materials Science and Engineering, Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 10000, Vietnam.
Faculty of Fundamental Sciences, Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 10000, Vietnam.
Dalton Trans. 2023 Sep 19;52(36):12704-12716. doi: 10.1039/d3dt01663c.
Phosphor-converted white light-emitting diodes (WLEDs) have received significant attention; however, the leaked light from their blue InGaN chips has an undesirable effect on human health. Hence, it is necessary to develop red, green, and blue-emitting phosphors, which can be excited by an NUV chip instead of a blue chip. Herein, green-emitting ZnO:Cu phosphors have been successfully synthesized by a simple and facile thermal diffusion method. The obtained powder shows a broad emission band peaking at 525 nm and a strong absorption peak at 377 nm. The ZnO:5%Cu phosphor annealed at 800 °C in 2 hours revealed a lifetime of 0.57 ms, an activation energy of 0.212 eV, and the highest emission intensity with (, ) CIE colour coordinates (0.3130, 0.5253). A WLED prototype has been fabricated by coating the ZnO:5%Cu phosphor on an NUV 375 nm LED chip, where this coated phosphor shows a high quantum efficiency (QE) of 56.6%. This is, so far, the highest reported QE value for ZnO-based phosphors. These results suggest that the ZnO:Cu phosphor could be an excellent candidate for NUV-pumped phosphor-converted WLED applications.
磷光转换白光发光二极管（WLED）已受到广泛关注；然而，其蓝色氮化铟镓（InGaN）芯片泄漏的光对人体健康有不良影响。因此，有必要开发可由近紫外（NUV）芯片而非蓝色芯片激发的红色、绿色和蓝色发光磷光体。在此，通过一种简单便捷的热扩散方法成功合成了绿色发光的ZnO:Cu磷光体。所获得的粉末显示出一个在525nm处达到峰值的宽发射带以及一个在377nm处的强吸收峰。在800℃下退火2小时的ZnO:5%Cu磷光体显示出0.57ms的寿命、0.212eV的激活能以及（0.3130，0.5253）的CIE色坐标下的最高发射强度。通过将ZnO:5%Cu磷光体涂覆在NUV 375nm LED芯片上制备了一个WLED原型，其中这种涂覆的磷光体显示出56.6%的高量子效率（QE）。这是迄今为止报道的基于ZnO的磷光体的最高QE值。这些结果表明，ZnO:Cu磷光体可能是NUV泵浦磷光转换WLED应用的极佳候选材料。
