Huang Wen-Tse, Hong Ling-Xuan, Liu Ru-Shi
Department of Chemistry, National Taiwan University, Taipei 106, Taiwan.
ACS Appl Mater Interfaces. 2023 Aug 23;15(33):39505-39512. doi: 10.1021/acsami.3c06257. Epub 2023 Aug 8.
Upgraded technology has realized miniaturization and promoted transformation in each field. Miniaturized light-emitting diode (LED) chips enable higher resolution and create a full sense of immersion in displays. Porous GaN is a structure that can reduce excitation light leakage and enhance the light conversion efficiency. Perovskite quantum dots with the highest optical density as candidate materials for loading in pores can significantly decrease the aggregation phenomenon and increase the path of light absorption. Here, the porous tunability is explored by electrochemical etching under a range of voltages, concentrations, and etching times with acid and base electrolytes, such as oxalic acid and potassium hydroxide. Based on scanning electron microscopy images, the distribution of the pores and the morphology of pore channels can be distinguished under acid and base etching. Larger pore sizes and distorted channels (∼680 nm) are presented on the oxalic acid-etched GaN chip. In contrast, smaller pore sizes and straight-deeper channels (∼5650 nm) are demonstrated on the GaN by potassium hydroxide etching. Therefore, the hybrid nanostructure is etched by oxalic acid and potassium hydroxide, separately. The green and red light conversion efficiencies of perovskite quantum dots pumped by a blue LED can be improved by 3 and 10 times, respectively, resulting in a color gamut of approximately 124%.
升级后的技术已实现各领域的小型化并推动了变革。小型化发光二极管（LED）芯片可实现更高分辨率，并在显示屏中营造出完全的沉浸感。多孔氮化镓是一种能够减少激发光泄漏并提高光转换效率的结构。具有最高光密度的钙钛矿量子点作为用于加载到孔隙中的候选材料，可显著减少聚集现象并增加光吸收路径。在此，通过在一系列电压、浓度以及使用草酸和氢氧化钾等酸碱电解质的蚀刻时间下进行电化学蚀刻来探索多孔可调性。基于扫描电子显微镜图像，在酸碱蚀刻下可以区分孔隙的分布和孔道的形态。草酸蚀刻的氮化镓芯片上呈现出更大的孔径和扭曲的通道（约680纳米）。相比之下，氢氧化钾蚀刻的氮化镓上展示出更小的孔径和更深的直通道（约5650纳米）。因此，分别用草酸和氢氧化钾蚀刻混合纳米结构。由蓝色LED泵浦的钙钛矿量子点的绿光和红光转换效率可分别提高3倍和10倍，从而实现约124%的色域。
