Band gap engineering in silicene: A theoretical study of density functional tight-binding theory |
| |
| Institution: | 1. Physics Group, Qazvin Branch, Islamic Azad University, Qazvin, Iran;2. Department of Physics, College of Technical and Engineering, Saveh Branch, Islamic Azad University, Saveh, Iran;1. University of Picardie, Laboratory of Condensed Matter Physics, Amiens 80039, France;2. Department of Theoretical Physics, National Research Center, Cairo 12622, Egypt;3. Division of Physics and Applied Physics, Nanyang Technological University, 637371 Singapore, Singapore;4. L. D. Landau Institute for Theoretical Physics, Moscow, Russia;1. Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan, Iran;2. Department of Electrical and Computer Engineering, University of Kashan, Kashan, Iran;1. Institute of Structural Mechanics, Bauhaus-Universität Weimar, Marienstr. 15, D-99423 Weimar, Germany;2. Chemical Engineering Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA;3. Institute for Materials Science and Max Bergman Center of Biomaterials, TU Dresden, 01062 Dresden, Germany;4. College of Civil Engineering, Department of Geotechnical Engineering, Tongji University, Shanghai, China;1. Central European Institute of Technology, Brno University of Technology, Purkyňova 123, CZ-61200 Brno, Czech Republic;2. Brno University of Technology, Faculty of Electrical Engineering and Communication, Department of Microelectronics, Technická 3058/10, CZ-61600 Brno, Czech Republic;3. Northwestern Polytechnical University, 127 West Youyi Road, Xi''an, Shaanxi, PR China;4. Division of Chemistry & Biological Chemistry, School of Physical Mathematical Science, Nanyang Technological University, Singapore 637371, Singapore;1. Domain of Mechanical Science and Technology, Graduate School of Science and Technology, Gunma University, Gunma, Japan;2. Department of Physics, Faculty of Science, Kasetsart University Bangkok 10900, Thailand |
| |
| Abstract: | In this work, we performed first principles calculations based on self-consistent charge density functional tight-binding to investigate different mechanisms of band gap tuning of silicene. We optimized structures of silicene sheet, functionalized silicene with H, CH3 and F groups and nanoribbons with the edge of zigzag and armchair. Then we calculated electronic properties of silicene, functionalized silicene under uniaxial elastic strain, silicene nanoribbons and silicene under external electrical fields. It is found that the bond length and buckling value for relaxed silicene is agreeable with experimental and other theoretical values. Our results show that the band gap opens by functionalization of silicene. Also, we found that the direct band gap at K point for silicene changed to the direct band gap at the gamma point. Also, the functionalized silicene band gap decrease with increasing of the strain. For all sizes of the zigzag silicene nanoribbons, the band gap is near zero, while an oscillating decay occurs for the band gap of the armchair nanoribbons with increasing the nanoribbons width. At finally, it can be seen that the external electric field can open the band gap of silicene. We found that by increasing the electric field magnitude the band gap increases. |
| |
| Keywords: | DFTB+ Silicene Nanoribbon Electronic properties Band gap |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
