Structural and electronic properties of lead chalcogenides from first principles
Structural and electronic properties of lead chalcogenides from first principles
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DOI：
10.1103/physrevb.75.195211
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发表时间：
2007-05-01
影响因子：
3.7
通讯作者：
Kresse, Georg
中科院分区：
文献类型：
--
作者：
Hummer, Kerstin;Gruneis, Andreas;Kresse, Georg
我们提出了从头计算的结构和电子性质的窄隙铅硫族化合物PbX（X=S，Se，和Te）。特别强调的是正确描述其特殊的电子性能相比，III-V和II-VI半导体，如非常小的幅度的带隙，不寻常的顺序的带隙内的系列[E-g（PbS）>E-g（PbTe）>E-g（PbSe）]，和高有效的电荷载流子质量。在标准密度泛函理论（DFT）中，局域密度近似（LDA）以及广义梯度近似（GGA）的交换相关势显然无法描述这些材料的能带结构的重要方面。这个问题是克服了应用方法，超越局部或半局部近似。我们表明，混合泛函是非常成功的电子，但也为结构性能给出正确的结果。晶格常数和体积模量以及基本带隙和有效质量与实验比在DFT-LDA/GGA中更好地一致。带隙的顺序也得到了适当的。为了比较，部分自洽GW（0）计算报告，产生高度准确的值的带隙。
We present ab initio calculations on the structural and electronic properties of the narrow-gap lead chalcogenides PbX (X=S, Se, and Te). Particular emphasis is put on the correct description of their exceptional electronic properties compared to III-V and II-VI semiconductors, such as the very small magnitude of the band gap, the unusual order of the band gaps within the series [E-g(PbS)>E-g(PbTe)>E-g(PbSe)], and the high effective charge-carrier masses. Within standard density-functional theory (DFT), the local-density approximation (LDA) as well as the generalized gradient approximation (GGA) to the exchange-correlation potential clearly fail to describe important aspects of the band structure of these materials. This problem is overcome by applying methods that go beyond the local or semilocal approximation. We show that hybrid functionals are very successful in giving the correct results for the electronic but also for the structural properties. The lattice constants and bulk moduli as well as the fundamental band gaps and effective masses are in much better agreement with experiment than within DFT-LDA/GGA. The order of the band gaps is also properly obtained. For comparison, partially self-consistent GW(0) calculations are reported, yielding highly accurate values for the band gaps.