报告题目 | First-Principles Theory of Epitaxial Film Growth |
报告人 | 张绳百 教授 |
报告人单位 | Department of Physics, Applied Physics, & Astronomy,Rensselaer Polytechnic Institute, USA |
报告时间 | 2017-03-30 |
报告地点 | 合肥微尺度物质科学国家实验室九楼会议室(9004) |
主办单位 | 合肥微尺度物质科学国家实验室、国际功能材料量子设计中心(ICQD) |
报告介绍 | Abstract:
Recent years witness the resurgence of van der Waals (vdW) epitaxy where two materials of drastically different physical properties are brought together. Ample examples exist for two-dimensional (2D) material on three-dimensional (3D) substrate and 2D material on 2D substrate, but few exists for 3D material on 2D substrate. Here, by a comparative study of CdTe film on layered NbSe2 and on graphene substrates, we illustrate the key role of interfacial dative bond between filled anion orbitals and empty cation orbitals in enhancing the vdW epitaxy. While understanding interfacial chemistry is important, to understand growth, a first-principles theory, which is simple enough yet encompasses the complexity of growth kinetics, is vitally important but currently lacking. Here, we develop a first-principles effective chemical potential approach that bridges between different stages of non-equilibrium growth from pre-nucleation, nucleation, to island growth. Application to molecular beam epitaxy (MBE) of Bi2Se3, which is also a layered material, reveals a high density of nuclei as the reason hindering the growth of large-size high-quality topological insulators, in qualitative agreement with experiment.
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