Impact of Surface Passivation on the Electronic Structure and Optical Properties of the Si1?xGex Nanowires
LAI Xin1,2, ZHANG Xi1,2**, ZHANG Yi-Xi1,2, XIANG Gang1,2**
1College of Physical Science and Technology, Sichuan University, Chengdu 610064 2Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064
Abstract：The electronic structures and optical properties of the [110]?oriented Si1?xGex nanowires (NWs) passivated with different functional groups (?H, ?F and -OH) are investigated by using first-principles calculations. The results show that surface passivation influences the characteristics of electronic band structures significantly: the band gap widths and types (direct or indirect) of the Si1?xGex NWs with different terminators show complex and robust variations, and the effective masses of the electrons in the NWs can be modulated dramatically by the terminators. The study of optical absorption shows that the main peaks of the parallel polarization component of Si1?xGex NWs passivated with the functional groups exhibit prominent changes both in height and position, and are red-shifted with respect to those of corresponding pure Si NWs, indicating the importance of both the terminators and Ge concentrations. Our results demonstrate that the electronic and optical properties of Si1?xGex NWs can be tuned by utilizing selected functional groups as well as particular Ge concentrations for customizing purposes.
(Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures)
引用本文:
. [J]. 中国物理快报, 2015, 32(02): 27301-027301.
LAI Xin, ZHANG Xi, ZHANG Yi-Xi, XIANG Gang. Impact of Surface Passivation on the Electronic Structure and Optical Properties of the Si1?xGex Nanowires. Chin. Phys. Lett., 2015, 32(02): 27301-027301.
2015, Vol. 32 
