Band Structure and High-pressure Measurements
Band Structure and High-pressure Measurements
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能带结构和高压测量
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
S. Sweeney
中科院分区：
文献类型：
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作者：
B. Murdin;A. Adams;S. Sweeney
半导体中电子能量与动量关系的确定对于预测其几乎所有性质都是必不可少的。在用于中红外应用的材料中，最简单的抛物线带近似通常是不够的。然而，相对直接的数值技术的基础上的k.p方法可以得到很好的预测的能带结构。理论能带结构可以与使用磁光和磁输运的实验进行比较，但是用于可控地调谐系统的最有用的工具之一是流体静力学应力。应变以一种相当简单的方式改变能带结构，主要是通过基本带隙的线性增加，因此它可以用来分离出依赖于带隙的效应。大量的文献已经建立了在压力下的近红外光电器件的研究。这些已被用来建立辐射和非辐射俄歇复合过程的变化与能带结构。结果预测，直接带隙小于自旋轨道间隙的III-V族中红外激光器的阈值电流密度应小于基于InP或GaAs的近红外激光器。发现这些预测与在大气压下以2.37 μm工作的InGaAsSb/AlGaAsSb中观察到的阈值电流密度及其随压力的变化一致。显然，高压技术为中红外设备的研究提供了令人兴奋的机会。
Determination of the electronic energy vs momentum relationship in semiconductors is essential for the prediction of almost all of their properties. In materials useful for mid-infrared applications, the simplest parabolic band approximations are usually insufficient. However relatively straight-forward numerical techniques based on the k.p method can yield good predictions for the bandstructure. The theoretical bandstructures can be compared with experiment using magneto-optics and magneto-transport, but one of the most useful tools for controllably tuning the system is hydrostatic stress. The strain modifies the bandstructure in a rather simple way, principally by a linear increase in the fundamental gap, and thus it can be used to separate out effects that depend on bandgap. A large literature has built up on the study of near-infrared optoelectronic devices under pressure. These have been used to establish the variations of the radiative and non-radiative Auger recombination processes with band structure. The results predict that III–V mid-IR lasers with direct band gaps less than the spin-orbit gap should have threshold current densities less than the near-IR lasers based on InP or GaAs. These predictions are found to be consistent with the threshold current density and its variation with pressure observed in InGaAsSb/AlGaAsSb operating at 2.37 µm at atmospheric pressure. Clearly high-pressure techniques provide exciting opportunities for the study of mid-infrared devices.