Ahmad Salameh, Hoang Khang, Mahanti S D
Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824-2320, USA.
Phys Rev Lett. 2006 Feb 10;96(5):056403. doi: 10.1103/PhysRevLett.96.056403. Epub 2006 Feb 8.
The nature of deep defect states, in general, and those associated with group III elements (Ga, In, Tl) in narrow band-gap IV-VI semiconductors (PbTe and PbSe), in particular, have been of great interest over the past three decades. We present ab initio electronic structure calculations that give a new picture of these states compared to the currently accepted model in terms of a negative-U Hubbard model. The Fermi surface pinning and why In-doped PbTe and related compounds show excellent high temperature thermoelectric behavior can be understood within the new picture.
一般来说，深缺陷态的性质，特别是与窄带隙IV-VI族半导体（PbTe和PbSe）中III族元素（Ga、In、Tl）相关的深缺陷态的性质，在过去三十年中一直备受关注。我们给出了从头算电子结构计算结果，与目前公认的基于负U Hubbard模型的模型相比，这些计算结果给出了这些态的新图像。在这个新图像中，可以理解费米面钉扎以及为什么In掺杂的PbTe和相关化合物表现出优异的高温热电性能。
