发光学报, 2017, 38 (11): 1420, 网络出版: 2017-12-25
ZnO量子点的制备及其在白光LED中的应用
Preparation of ZnO Quantum Dots and Their Applications in White LED
ZnO量子点 黄绿光发射 湿化学法 ZnO量子点/Al2O3/p-GaN异质结构 白光LED ZnO QDs yellow-green emission wet chemistry method ZnO QDs/Al2O3/p-GaN heterostructure white-LED
摘要
利用湿化学方法制备合成ZnO量子点, 通过改变合成条件(反应时间、反应物浓度、反应温度)对量子点的尺寸及发光性能进行调控。利用透射电子显微镜、吸收光谱、荧光光谱等表征手段, 探讨了合成条件对ZnO量子点光学性质的影响, 并优化出适用于构建白光LED器件的最佳合成条件。研究结果表明, 在反应温度为20 ℃、反应时间为3 h、前驱体Zn(OAc)2和LiOH反应浓度比为2∶1时获得的ZnO量子点较为稳定, 并在紫外光激发下发出明亮的黄绿色光。在此基础上, 以该ZnO量子点为有源层、p-GaN∶Mg基片为空穴注入层、非晶Al2O3薄膜为电子阻挡层构造了p-i-n型异质结LED, 在正向注入电流为5 mA时, 获得了来自于器件的白光发射, 其色坐标为(0.28,0.30), 色温为9 424 K。
Abstract
ZnO quantum dots (ZnO QDs) were fabricated by wet chemistry method. By varying the synthesis conditions (reaction time, reagent concentration ratio and reaction temperature), the size and luminescence properties of ZnO QDs can be effectively controlled. Transmission electron microscopy, UV-Vis absorption spectra and fluorescence spectra were employed to analyze the influence of preparation conditions on optical properties of the synthesized ZnO QDs, and a set of optimized synthesis condition was obtained for the following fabrication of white-LED device. The physical mechanism of the device electroluminescence (EL) was investigated via the measurements of current-voltage curves and EL spectra. The results show that stable ZnO QDs can be obtained at room temperature when the synthesis condition is set as: concentration ratio of Zn(OAc)2 to LiOH is 2∶1 and reaction time is 3 h. Finally, a p-i-n type LED was constructed by employing p-GaN∶Mg wafer and Al2O3 thin film respectively as hole injection layer and electron blocking layer, and a white EL emission under forward injection current of 5 mA was achieved, where the CIE is located at (0.28, 0.30) and the color temperature is calculated to be 9 424 K.
朱菲菲, 杨柳, 刘凯, 刘为振, 张涔, 徐海阳, 马剑钢. ZnO量子点的制备及其在白光LED中的应用[J]. 发光学报, 2017, 38(11): 1420. ZHU Fei-fei, YANG Liu, LIU Kai, LIU Wei-zhen, ZHANG Cen, XU Hai-yang, MA Jian-gang. Preparation of ZnO Quantum Dots and Their Applications in White LED[J]. Chinese Journal of Luminescence, 2017, 38(11): 1420.