Magnetophotoluminescence study of the Ga0.5In0.5P/GaAs heterointerface with a ordering-induced two-dimensional electron gas
Magnetophotoluminescence study of the Ga0.5In0.5P/GaAs heterointerface with a ordering-induced two-dimensional electron gas
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有序诱导二维电子气 Ga0.5In0.5P/GaAs 异质界面的磁光致发光研究
DOI：
10.1103/physrevb.66.195317
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发表时间：
2002
影响因子：
3.7
通讯作者：
K. Oe
中科院分区：
文献类型：
--
作者：
K. Yamashita;T. Kita;Y. Matsuura;O. Wada;C. Geng;F. Scholz;H. Schweizer;K. Oe
我们研究了在Ga 0 . 5在0。5 P/GaAs-单异质界面。Ga 0中的长程有序。五比零。5 P引起异质界面GaAs侧的电子积累。系统地测量了未掺杂的无序和有序Ga 0 . 5在0。5个P/GaAs样品。有序样品的PL谱显示了与掩埋在异质界面处的三角势中的量子化电子态和费米边奇异性相关的信号，相反，无序样品显示了高质量块状GaAs的典型PL谱。磁光致发光谱表明，平行和垂直于异质界面之间的约化激子质量是各向异性的。我们发现在垂直磁场下，PL强度和跃迁能量都有明显的光学Shubnikov-de哈斯（SdH）振荡。这些PL特征表明，在异质界面处积累的电子充当二维电子气（2DEG）。根据观测到的SdH振荡周期，推导出2DEG的面载流子密度为1.20 × 1012 cm - 2 .
We studied two-dimensional properties of electrons accumulated at the GaAs side of Ga 0 . 5 In 0 . 5 P/GaAs-single heterointerface. Long-range ordering in Ga 0 . 5 In 0 . 5 P causes the electron accumulation at the GaAs side of the heterointerface. Photoluminescence (PL) spectra of GaAs have been systematically measured for undoped unordered and ordered Ga 0 . 5 In 0 . 5 P/GaAs samples. A PL spectrum of the ordered sample shows signals related to the quantized electron state in a triangular potential buried at the heterointerface and the Fermi-edge singularity, in contrast that the unordered sample shows a typical PL spectrum of a high-quality bulk GaAs. Magneto-PL spectra indicate that the reduced exciton masses between parallel and perpendicular to the heterointerface are anisotropic. We found clear optical Shubnikov-de Haas (SdH) oscillations in both the PL intensity and the transition energy under the perpendicular magnetic field. These PL features demonstrate that the electrons accumulated at the heterointerface act as two-dimensional electron gas (2DEG). The sheet-carrier density of the 2DEG is deduced from the period of the observed SdH oscillation and it found to be ∼ 1.20 × 10 1 2 cm - 2 .