Density functional theory based study of the structural and electronic properties of graphitic heterostructures

  • Melanie David Physics Department, De La Salle University
Keywords: Density functional theory, Computational physics


With the trend of miniaturization and maximizing the potential of nanomaterials, the properties of important materials in electronic devices such as graphene and silicene have been widely investigated. This presentation aims to provide computational information for the achievement of this goal by studying the structural stability and electronic properties of hexagonal-boron nitride on graphene (h-BN/G) hetero-bilayer and silicene on hexagonal-boron nitride on graphene (Si/h-BN/G) heterostructure using density functional theory. The calculations were performed through the Vienna Ab Initio Simulation Package (VASP) implemented with three different approximations namely, LDA, GGA, and GGA with Tkatchenko-Scheffler van der Waals (vdW) correction. From the calculations, the h-BN/G hetero-bilayer and Si/h-BN/G heterostructures were found to be computationally stable relative to the experimental binding energy and interlayer distance between graphitic layers. Moreover, it was observed that layers of graphitic structures interact through the Van der Waals forces (vdW), thus calculations of such structures must be done with vdW corrections. Lastly, the application of perpendicular strain modified the band gap and Dirac cone shifting of the system.  These characteristics suggested that the hetero-bilayer and heterostructure have great potential for electronic device applications.

About the Speaker

Melanie David is an Associate Professor of the Physics Department under the College of Science at De La Salle University (DLSU). She is presently the Director of Center for Natural Science and Environmental Research (CENSER) and a member of the Advanced Nanomaterials Investigation by Molecular Simulations (ANIMoS) and Microalgal Systematics and Applied Phycology Research Unit (MSAPRU). She is also the Coordinator of the Osaka University (OU) Satellite Office at DLSU and serves as a linkage faculty between OU and DLSU.
Her research centers on the computational modeling of nanoscale materials for design and functionalities. In particular, she works on carbon nanotubes, thermoplastics on metals, semiconducting and magnetic materials for electronic and magnetic devices, fuel cells, energy, and environment applications.
In addition to first principles calculations, her research group is also using molecular dynamics to understand the mechanism behind and formulate solutions for bioenergy processing and microalgae drying. Their studies on microalgae is part of several projects supported by different agencies within and outside the university, such as the DLSU-University Research Coordination Office, CHEd PHERNet Sustainability Studies program, and the USAID Science, Technology, Research and Innovation for Development (STRIDE) Program.