Study of InGaN/GaN quantum dot systems by TEM techniques and photoluminescence spectroscopy
Study of InGaN/GaN quantum dot systems by TEM techniques and photoluminescence spectroscopy
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利用 TEM 技术和光致发光光谱研究 InGaN/GaN 量子点系统
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
A. Harvey
中科院分区：
文献类型：
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作者：
R. Kashtiban;U. Bangert;B. Sherliker;M. Halsall;A. Harvey
通过透射电子显微镜 (TEM) 和光致发光 (PL) 技术研究了在 c 面蓝宝石上采用 MOCVD 技术制备的 InGaN/GaN 多层量子点结构。通过能量过滤 TEM (EFTEM) 和高角度环形暗场 (HAADF) 扫描 TEM 观察到铟波动范围为 1-4 nm。在HAADF图像中观察到在螺纹位错终止处存在具有成核中心的V形缺陷。晶格 HRTEM 图像也有证据表明在低密度下形成了大量子点。 PL 测量通过观察低功率下的单条锐线以及较高功率激励下的典型饱和行为进一步证实了这一点。
InGaN/GaN multilayer quantum dot structures produced by MOCVD techniques on c-plane sapphire were studied by transmission electron microscopy (TEM) and photoluminescence (PL) techniques. Indium fluctuations ranging from 1-4 nm were observed with both energy filtered TEM (EFTEM) and high angle annular dark field (HAADF) scanning TEM. The existence of V-shaped defects with nucleation centres at the termination of threading dislocation were observed in HAADF images. There was also evidence of the formation of large quantum dots at low densities from lattice HRTEM images. This was further confirmed by PL measurements through the observation of a single sharp line at low power with the typical saturation behaviour at higher power excitation.