纳米柱高度对GaN基绿光LED光致发光谱的影响  

Effects of The Height of Nanorod Structure on The Photoluminescence Spectra of GaN-based Green LED

作　　者：黄华茂[1,2] 黄江柱 胡晓龙[1] 王洪[1,2] 

机构地区：[1]华南理工大学广东省光电工程技术研究开发中心物理与光电学院,广东广州510640 [2]广州现代产业技术研究院,广东广州511458

出　　处：《发光学报》2016年第8期967-972,共6页Chinese Journal of Luminescence

基　　金："863"国家高技术研究发展计划(2014AA032609);国家自然科学基金(61404050);广东省科技计划(2014B010119002;2016A010103011);广州市珠江科技新星专项(201610010038);中央高校基本科研业务费专项资金(2015ZM131)资助项目

摘　　要：纳米柱结构是释放高In组分InGaN/GaN绿光LED量子阱层应变的有效方法。本文采用自组装的聚苯乙烯微球掩模、感应耦合等离子体干法刻蚀和KOH溶液的湿法腐蚀,在GaN基绿光LED外延片上制备了3种高度的纳米柱结构,通过扫描电子显微镜观察纳米柱结构的形貌,并测试了常温和10 K低温时的光致发光谱(PL)。结果表明:应变释放对压电场的影响显著,使得纳米柱结构样品的内量子效率(IQE)提高,PL谱峰值波长蓝移;应变在量子阱中的不均匀分布还使得PL谱半高全宽(FWHM)展宽。与普通平面结构相比,高度为747 nm的纳米柱结构可使得IQE提升917%,PL谱峰值波长蓝移18 nm、FWHM展宽7 nm。另外,纳米柱结构样品的有源区有效面积减小可使得PL谱FWHM减小。Nanorod structure is an effective method to release the strain in multiple quantum wells of InGaN / GaN green LED with high In component. In this paper,the natural lithography with self-assembled polystyrene microspheres,inductively coupled plasma dry etching and wet-etching using KOH aqueous solution were used to fabricate the nanorod structure with three heights in Ga N-based green LED epitaxial wafers. The morphology was observed by scanning electron microscope,and the photoluminescence（ PL）spectra at room temperature and 10 K low temperature were characterized. It is shown that the strain relaxation significantly affect the piezoelectric field,thereby the nanorod structure leads to a promotion of the wafers＇ internal quantum efficiency（ IQE） and blue-shift of the peak wavelengths of PL spectra,and the nonuniform distribution of the strain causes a broadening of the FWHM（ full width at half maximum）. Compared with the ordinary planar structure,the nanorod structure with the height of 747 nm induces an enhancement of 917% for the IQE,a blue-shift of 18 nm for the peak wavelengths of PL spectrum,and a broadening of 7 nm for the FWHM. The results also indicate that the decreasing of effective active area of samples with nanorod structure may reduce the FWHM.

关 键 词：GAN基LED 绿光LED 纳米柱结构 光致发光谱 

分 类 号：TN303[电子电信—物理电子学]