Two novel SiC phases: structure, mechanical, and transport properties

Abstract

Two novel phases of SiC are put forward in this paper, in which the crystal structural, mechanical, and electronic properties, as well as effective mass and carrier mobility of SiC in the Pnnm phase ( Pnnm -SiC) and Pm phase ( Pm -SiC) are researched utilizing first principles calculations. Both of the novel SiC phases are certificated to have good mechanical and dynamic stability. Through analysis of the three-dimensional perspective of Young’s modulus, shear modulus and Poisson’s ratio, visible anisotropies of mechanical properties are found. The band structure calculations predict two wide bandgap semiconductors, that the Pnnm -SiC is an indirect with a bandgap value of 3.12 eV, While the Pm -SiC is a quasi-direct with a bandgap value of 2.64 eV, which indicates the Pm -SiC has a higher application potential in the optoelectronic device area. An extremely large electronic mobility (7200 cm ^2 V ^−1 s ^−1 ) is found in the Pnnm -SiC. Based on the wide band gap, large carrier mobility, good mechanical and dynamic stability, the Pnnm -SiC is a promising material in the field of high performance electronic device in harsh environment.

Keywords

• density functional theory
• SiC
• mechanical properties
• anisotropic properties