Liao Che-Hao, Chang Wen-Ming, Chen Horng-Shyang, Chen Chih-Yen, Yao Yu-Feng, Chen Hao-Tsung, Su Chia-Ying, Ting Shao-Ying, Kiang Yean-Woei, Yang C C
Institute of Photonics and Optoelectronics, Department of Electrical Engineering, National Taiwan University, 1, Roosevelt Road, Section 4, Taipei, 10617 Taiwan.
Opt Express. 2012 Jul 2;20(14):15859-71. doi: 10.1364/OE.20.015859.
With the nano-imprint lithography and the pulsed growth mode of metalorganic chemical vapor deposition, a regularly-patterned, c-axis nitride nanorod (NR) array of quite uniform geometry with simultaneous depositions of top-face, c-plane disc-like and sidewall, m-plane core-shell InGaN/GaN quantum well (QW) structures is formed. The differences of geometry and composition between these two groups of QW are studied with scanning electron microscopy, cathodoluminescence, and transmission electron microscopy (TEM). In particular, the strain state analysis results in TEM observations provide us with the information about the QW width and composition. It is found that the QW widths are narrower and the indium contents are higher in the sidewall m-plane QWs, when compared with the top-face c-plane QWs. Also, in the sidewall m-plane QWs, the QW width (indium content) decreases (increases) with the height on the sidewall. The observed results can be interpreted with the migration behaviors of the constituent atoms along the NR sidewall from the bottom.
通过纳米压印光刻技术和金属有机化学气相沉积的脉冲生长模式，形成了具有规则图案的、几何形状相当均匀的c轴氮化物纳米棒（NR）阵列，同时沉积了顶面、c面盘状和侧壁、m面核壳InGaN/GaN量子阱（QW）结构。利用扫描电子显微镜、阴极发光和透射电子显微镜（TEM）研究了这两组量子阱在几何形状和组成上的差异。特别是，TEM观察中的应变状态分析结果为我们提供了有关量子阱宽度和组成的信息。研究发现，与顶面c面量子阱相比，侧壁m面量子阱的量子阱宽度更窄，铟含量更高。此外，在侧壁m面量子阱中，量子阱宽度（铟含量）随侧壁高度降低（增加）。观察结果可以用组成原子从底部沿纳米棒侧壁的迁移行为来解释。
