Different roles of carbon and silicon vacancies in silicon carbide bulks and nanowires

作者：Li, Shu-Long; Li, Ya-Lin; Li, Yan-Jing; Gong, Pei; Fang, Xiao-Yong^*

来源：International Journal of Modern Physics B, 2017, 31(23): 1750173.

DOI：10.1142/S0217979217501739

• SiC nanowire
• vacancy
• electronic structure
• optical properties
• first-principles theory

We investigated the effects of carbon and silicon vacancies on the electronic structure and optical properties of pure silicon carbide (SiC) bulks and nanowires (NWs) based on density functional theory in CASTEP module. Calculation results showed that vacancies only slightly influenced structure and stability, particularly those of NWs. By contrast, effects on electronic function and optical properties were more notable. We found that the energy gaps of SiC bulks and NWs decreased with increased vacancies redistributing the electron density, which critically contributed to the formation of C-C and Si-Si bonds. The dielectric loss of SiC bulks and NWs in the ultraviolet region was primarily attributed to conductivity, whereas the loss in this region was due to the polarization of dangling bonds.

• 出版日期2017-9-20
• 单位燕山大学