Growth condition dependence of direct bandgap in β-FeSi_2 epitaxial films grown by molecular beam epitaxy
Growth condition dependence of direct bandgap in β-FeSi_2 epitaxial films grown by molecular beam epitaxy
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分子束外延生长β-FeSi_2外延薄膜直接带隙的生长条件依赖性
DOI：
10.1016/j.phpro.2012.01.002
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
K.Noda
中科院分区：
文献类型：
--
作者：
Y. Terai;K. Noda;K.Noda
研究了不同生长条件下分子束外延（MBE）生长的β-FeSi2外延薄膜的直接带隙能（Eg）和晶格变形。当MBE生长过程中Si/Fe通量比变得小于Si/Fe = 2.0时，晶格常数偏离β-FeSi2单晶的晶格常数，这表明在较低Si/Fe比下晶格变形增强。在光反射 (PR) 测量中，随着晶格变形的增强，PR 光谱转向较低的光子能量。这些结果表明，根据生长条件，β-FeSi2 外延膜的 Eg 通过晶格变形而改变。
Direct bandgap energy (Eg) and lattice deformations were investigated in β-FeSi2 epitaxial films grown by molecular beam epitaxy (MBE) with different growth condition. As Si/Fe flux ratio during the MBE growth became smaller than Si/Fe = 2.0, the lattice constants deviated from those of β-FeSi2 single crystal, which indicated an enhanced lattice deformation at the lower Si/Fe ratio. In photoreflectance (PR) measurements, the PR spectra shifted to lower photon energy with the enhanced lattice deformation. These results revealed that the Eg of β-FeSi2 epitaxial film was modified by the lattice deformation depending on the growth condition.