Ab initio calculations of the optical properties of crystalline and liquid InSb
Ab initio calculations of the optical properties of crystalline and liquid InSb
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DOI：
10.1063/1.4935438
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发表时间：
2015-11
期刊：
影响因子：
1.6
通讯作者：
H. Sano;G. Mizutani
中科院分区：
文献类型：
--
作者：
H. Sano;G. Mizutani
对InSb的电子和光学性质进行了晶态和液态的从头算计算。通过从头算分子动力学模拟，得到了两套InSb液体在900K时的原子结构模型。为了减少液体模型中结构特性的影响，对两种液体模型所对应的两组计算的电子和光学性质进行了平均。计算结果表明，由于从晶体到液体的相变，费米能级附近的态密度增加。结果，在费米能级附近打开的能隙消失了。因此，光学性质从半导体行为转变为金属行为。也就是说，由于InSb的熔化，带间跃迁峰消失，在光学介电函数中观察到类Drude色散。用于蓝光光盘系统的3.06 eV光子能量的光吸收由于InSb的熔化而增加。这种光学吸收的增加被认为是由于低于2 eV的光学跃迁增加所致。
Ab initio calculations of the electronic and optical properties of InSb were performed for both the crystalline and liquid states. Two sets of atomic structure models for liquid InSb at 900 K were obtained by ab initio molecular dynamics simulations. To reduce the effect of structural peculiarities in the liquid models, an averaging of the two sets of the calculated electronic and optical properties corresponding to the two liquid models was performed. The calculated results indicate that, owing to the phase transition from crystal to liquid, the density of states around the Fermi level increases. As a result, the energy band gap opening near the Fermi level disappears. Consequently, the optical properties change from semiconductor to metallic behavior. Namely, owing to the melting of InSb, the interband transition peaks disappear and a Drude-like dispersion is observed in the optical dielectric functions. The optical absorption at a photon energy of 3.06 eV, which is used in Blu-ray Disc systems, increases owing to the melting of InSb. This increase in optical absorption is proposed to result from the increased optical transitions below 2 eV.