Transmission Electron Microscopy and Photoluminescence Characterization of InAs Quantum Wires on Vicinal GaAs(110) Substrates by Molecular Beam Epitaxy
Transmission Electron Microscopy and Photoluminescence Characterization of InAs Quantum Wires on Vicinal GaAs(110) Substrates by Molecular Beam Epitaxy
复制标题
分子束外延法对邻位 GaAs(110) 衬底上 InAs 量子线的透射电子显微镜和光致发光表征
DOI：
10.1143/jjap.38.4673
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发表时间：
1999
影响因子：
1.5
通讯作者：
H. Nakashima
中科院分区：
文献类型：
--
作者：
S. Torii;K. Bando;B. Shim;K. Maehashi;H. Nakashima
InAs量子线已经通过分子束外延在邻近的GaAs(110)表面上自然形成，具有巨大的台阶。透射电子显微镜观察显示，由于 InAs-GaAs 晶格不匹配，粗线 (>4 ML) 会出现高密度堆垛层错和莫尔条纹。从莫尔条纹分离来看，发现厚的 InAs 线是完全松弛的。对于细线 (<4 ML)，没有观察到缺陷。对 InAs 线观察到的强偏振光致发光 (PL) 证实了载流子对量子线结构的限制以及大晶格失配引起的应变效应。在 PL 的激发强度依赖性中观察到相当大的能量变化，表明存在很大的不均匀性。
InAs quantum wires have been naturally formed on vicinal GaAs(110) surfaces with giant steps by molecular beam epitaxy. Transmission electron microscope observations reveal the high density of stacking faults and the moire fringe for thick wires (>4 ML) due to the large InAs–GaAs lattice mismatch. From the moire fringe separation, thick InAs wires are found to be completely relaxed. No defect is observed for thin wires (<4 ML). Strongly polarized photoluminescence (PL) observed for InAs wires confirms the carrier confinement to the quantum wire structures and the strain effect induced by the large lattice mismatch. A considerable energy shift is observed in the excitation intensity dependence of PL, indicating large nonuniformity.