半导体中电荷缺陷计算的实际维数独立方法

活动时间： 06月23日09时00分       

地            点  ： 腾讯会议（会议ID：797 668 555）

讲座内容：

First-principles calculations of charged defectshave become a cornerstone of research in semiconductors and insulators byproviding insights into their fundamental physical properties. But currentstandard approach using the so-called “jellium model” has encountered bothconceptual ambiguity and computational difficulty, especially forlow-dimensional semiconducting materials. In this presentation, we propose aphysical, straightforward, and dimension-independent universal model tocalculate the formation energies of charged defects in both three-dimensional(3D) bulk and low-dimensional semiconductors. Within this model, the ionizedelectrons or holes are placed on the realistic host band-edge states instead ofthe virtual jellium state, therefore, rendering it not only naturally keeps thesupercell charge neutral, but also has clear physical meaning. This realisticmodel reproduces the same accuracy as the traditional jellium model for most ofthe 3D semiconducting materials, and remarkably, for the low-dimensionalstructures, it is able to cure the divergence caused by the artificiallong-range electrostatic energy introduced in the jellium model, and hence givesmeaningful formation energies of defects in charged state and transition energylevels of the corresponding defects. Our realistic method, therefore, will havesignificant impact for the study of defect physics in all low-dimensionalsystems including quantum dots, nanowires, surfaces, interfaces, and 2Dmaterials.

主讲人介绍：

邓惠雄，中科院半导体所研究员，国家优秀青年基金获得者，中科院创新促进会会员。长期从事半导体物理、半导体缺陷物理、半导体光电功能材料的物性探究与设计的研究工作。迄今已经在Nature Energy、 Phys. Rev. Lett.、Phys. Rev. X、Phys. Rev. B、Adv. Mater.等期刊上发表SCI论文60多篇。

发布时间：2020-06-18 15:28:15