報告題目：Stability of Asymmetric Polar or Semipolar Surface, Interface and Edges: from Algorithm to Practices
報告人：Prof. Junyi Zhu (朱駿宜教授), Chinese Univ. of Hong Kong
In this talk, I’ll briefly introduce our recent development of the new algorithm on the calculations of absolute formation energy of asymmetric polar/semipolar surfaces, interfaces, and edges of compound semiconductors. The new algorithm improved the accuracy of the formation energy for an order of magnitude comparing with the standard wedge method. Based on this new algorithm, the surface, interface, grain boundary formation energy, and the wetting condition of heterostructures can be estimated accurately. Further, a new strategy based on surfactant H tuning of GaN on ZnO substrate is proposed. In the end, with a proper estimation of H passivation and entropy effects, the equilibrium shapes of BN nano clusters are correctly obtained. We found that only when accurate algorithm, H passivation, and temperature effects are all considered, can the correct equilibrium shape of BN nano cluster be obtained.
Dr. Junyi Zhu is an assistant professor at Department of Physics, Chinese University of Hong Kong. He received his BSc in Physics from Peking University in 1998, and PhD in Materials Science and Engineering from University of Utah in 2009. His main research interests include first principles studies of electronic, magnetic, thermodynamic, and kinetic properties of defects, dopants, surfaces and interfaces in semiconductors and magnetic materials.