Predicted band-gap pressure coefficients of all diamond and zinc-blende semiconductors: Chemical trends
Predicted band-gap pressure coefficients of all diamond and zinc-blende semiconductors: Chemical trends
复制标题
DOI：
10.1103/physrevb.60.5404
复制
发表时间：
1999-08-15
影响因子：
3.7
通讯作者：
Zunger, A
中科院分区：
文献类型：
--
作者：
Wei, SH;Zunger, A
我们用第一性原理能带结构方法系统地研究了所有IV族、m-V族和II-VI族半导体的带隙压力系数的化学变化趋势。我们还计算了价带顶（VBM）和导带底（CBM）的“绝对”形变势。我们发现：（1）γ（6c）CBM的体积形变势通常很大，并且总是负值;（2）γ（8 nu）VBM态的体积形变势通常很小，对于有d价轨道占据的化合物为负值，而对于没有d价轨道占据的化合物为正值。关于带隙压力系数的化学趋势，我们发现（3）a（p）（Gamma-Gamma）随着离子度的增加而减小（例如，从Ge -> GaAs -> ZnSe），（4）α（p）（γ-γ）随着阴离子原子序数的增加而显著增加（例如，从GaN --> GaP --> GaAs --> GaSb），（5）α（p）（γ-γ）随着阳离子原子序数的增加而略微降低（例如，从AlAs → GaAs → InAs），（6）α（p）（γ-L）的变化相对较小，并遵循与α（p）（γ-γ）类似的趋势，以及（7）α（p）（γ-χ）的幅度较小，通常为负，但有时对于包含第一行元素的化合物略为正。我们计算的化学趋势解释的原子价轨道的能级和这些轨道之间的耦合。据此，我们建议修正压力系数的“经验法则”。[S0163-1829（99）00532-9]。
We have studied systematically the chemical trends of the band-gap pressure coefficients of all group IV, m-V, and Il-VI semiconductors using first-principles band-structure method. We have also calculated the individual "absolute" deformation potentials of the valence-band maximum (VBM) and conduction-band minimum (CBM). We find that (I) the volume deformation potentials of the Gamma(6c) CBM are usually large and always negative, while (2) the volume deformation potentials of the Gamma(8 nu) VBM state are usually small and negative for compounds containing occupied valence d state but positive for compounds without occupied valence d orbitals. Regarding the chemical trends of the band-gap pressure coefficients, we find that (3) a(p)(Gamma-Gamma) decreases as the ionicity increases (e.g., from Ge --> GaAs --> ZnSe), (4) a(p)(Gamma-Gamma) increases significantly as anion atomic number increases (e.g., from GaN --> GaP --> GaAs --> GaSb), (5) a(p)(Gamma-Gamma) decreases slightly as cation atomic number increases (e.g., from AlAs --> GaAs --> InAs), (6) the variation of a(p)(Gamma-L) are relatively small and follow similar trends as a(p)(Gamma-Gamma), and (7) the magnitude of a(p)(Gamma-chi), small and usually negative, but are sometimes slightly positive for compounds containing first-row elements. Our calculated chemical trends are explained in terms of the energy levels of the atomic valence orbitals and coupling between these orbital. In light of the above, we suggest that "empirical rule" of the pressure coefficients should be modified. [S0163-1829(99)00532-9].