类阳极氧化铝纳米结构LED的研究

doi:10.15541/jim20190246

摘要/Abstract

摘要：

LED具有高效、节能和环保等优势, 广泛应用于照明领域, 提高LED的发光效率一直是该领域的研究难点与热点。为了降低GaN材料与空气界面的全反射现象, 提高光提取效率, 本研究探讨了类阳极氧化铝AAO(Anodic aluminum oxide)纳米结构LED器件的制备和性能。通过电感耦合等离子体(Inductively coupled plasma, ICP)刻蚀工艺的调控, 在p-GaN层表面制备了大面积有序孔洞纳米结构阵列, 可获得孔径250~500 nm, 孔深50~150 nm的准光子晶体结构, 从而大幅提高了LED的发光强度, 其中孔径400 nm、深度150 nm的纳米阵列LED相比于没有纳米阵列的LED发光强度提高达3.5倍。

关键词: 电感耦合等离子体(ICP)刻蚀, GaN, LED, 准光子晶体, 阳极氧化铝(AAO)模板

Abstract:

LED has the advantages of high efficiency, energy saving and environmental protection. It is widely used in the field of lighting. Improving the luminous efficiency of LED has always been a research difficulty and hot spot in this field. To reduce the total reflection phenomenon between GaN material and air and to improve the light extraction efficiency, fabrication and properties of the anodized aluminum oxide (AAO) nanostructured LED device were studied. Through inductively coupled plasma (ICP) etching process, large-area ordered pore nanostructure arrays were successfully fabricated on the surface of p-GaN layer, and the quasi-photonic crystal structure with apertures of 250-500 nm and pore depths of 50-150 nm were obtained. The crystal structure greatly increases the luminous intensity of the LED, and the nano-array LED with pore diameter of 400 nm and depth of 150 nm is improved by 3.5 times in contrast to the LED without the nano-array.

Key words: inductively coupled plasma etching, GaN, LED, quasi-photonic crystal, anodic aluminum oxide membrane

中图分类号:

TN383

郑雪, 江睿, 李谦, 王伟哲, 徐智谋, 彭静. 类阳极氧化铝纳米结构LED的研究[J]. 无机材料学报, 2020, 35(5): 561-566.

ZHENG Xue, JIANG Rui, LI Qian, WANG Weizhe, XU Zhimou, PENG Jing. Research on Anodic Aluminum Oxide Nanostructured LEDs[J]. Journal of Inorganic Materials, 2020, 35(5): 561-566.

图/表 7

图1 纳米结构LED芯片制备流程图

Fig. 1 Schematic of the fabrication process of nanostructured LED chip

表1 ICP刻蚀的参数设置

Table 1 Parameters of the ICP etching

Materials	Gas flow/sccm		Pressure/Pa	Power/W	Time/s
Al₂O₃	BCl₃	40	1.0664	400	240
Al₂O₃	Ar	10	1.0664	400	240
GaN	BCl₃	20	0.5332	550	25
GaN	Cl₂	30	0.5332	550	25

图2 分别刻蚀60、120、180和240 s后的AAO膜的SEM照片(a1~a4)和分别统计(a1~a4)中的孔径分布图(b1~b4)

Fig. 2 SEM images of the AAO membrane which pore widening by increasing etching time and calculated scale distribution of the pore diameter in (a1-a4) (a1) 60 s; (a2) 120 s; (a3) 180 s; (a4) 240 s. (b1-b4) correspond to (a1-a4)

图3 孔径随刻蚀时间的变化曲线(a)和刻蚀速率随孔径的变化曲线(b)

Fig. 3 Curve of the pore diameter with the etching time (a) and curve of the etching rate with the pore diameter (b)

表2 ICP刻蚀不同时长时的孔径与刻蚀速率统计表

Table 2 Statistics of pore diameter and etching rate with ICP etching for different durations

t/s	D/nm	V/(nm·s^-1)
0	251.37	0.141
30	259.85	0.159
60	270.48	0.199
90	283.70	0.255
120	301.12	0.313
150	321.28	0.368
180	345.29	0.426
210	372.45	0.476
240	402.45	0.500
270	432.53	0.501

图4 纳米结构LED芯片SEM照片

Fig. 4 SEM images of nanostructured LED chip (a) Cross sectional view; (b) Oblique view

图5 不同孔径(a)和不同深度的纳米结构LED的发光谱图(b)

Fig. 5 PL spectra of nanostructured LEDs with different pore diameter (a) and different depths (b)

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