Bowing of the band gap and spin-orbit splitting energy in BGaAs
Bowing of the band gap and spin-orbit splitting energy in BGaAs
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DOI：
10.1088/2053-1591/ab62e9
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发表时间：
2019-12-01
影响因子：
2.3
通讯作者：
Bank, S. R.
中科院分区：
文献类型：
--
作者：
Kudrawiec, R.;Polak, M. P.;Bank, S. R.
通过分子束外延在砷化镓（GaAs）和磷化镓（GaP）衬底上生长了硼浓度高达17.7%的硼镓砷（BGaAs）层，并利用光反射（PR）光谱进行了研究。在光反射光谱中观察到了价带（重空穴、轻空穴和自旋 - 轨道分裂带）与导带之间的直接光学跃迁。根据光反射研究确定的带隙和自旋 - 轨道分裂的弯曲参数分别为3.6±0.2电子伏特和0.2±0.1电子伏特。这些值与使用最先进的第一性原理密度泛函方法所确定的值（b(dir)=3.5±0.1电子伏特和b(SO)=0.06±0.02电子伏特）非常接近。此外，对间接带隙进行了理论研究，确定弯曲参数为2.3±0.？电子伏特，硼镓砷中直接带隙和间接带隙的交叉点在硼含量约为12%处。
BGaAs layers with the boron concentration up to 17.7% have been grown by molecular beam epitaxy on GaAs and GaP substrates and studied by photoreflectance (PR) spectroscopy. The direct optical transitions between the valence band (heavy hole, light hole, and the spin-orbit split-off band) and the conduction band have been observed in PR spectra. The bowing parameter for the band gap and the spin-orbit splitting has been determined from PR studies to be 3.6 0.2 and 0.2 0.1 eV, respectively. These values are very close to those determined using state-of-the-art first principle density functional methods (b(dir) = 3.5 0.1 eV and b(SO) = 0.06 0.02 eV). In addition, the indirect band gap has been examined theoretically and the bowing parameter has been determined to be 2.3 0. eV, with the crossing between the direct and indirect gap in BGaAs at similar to 12% B.