Prediction of the Structural, Mechanical, and Physical Properties of GaC: As a Potential Third-Generation...

Similar to GaN and SiC semiconductors, GaC may be a potential semiconductor because of the mixed elemental features of Ga and C. Unfortunately, the phase stability and mechanical and physical properties of GaC are unknown. To search for novel third-generation semiconductors, the present study delves into an in-depth analysis of the structural stability and electronic and optical properties of GaC by DFT calculations. Similar to GaN, three GaC phases are discussed. It is found that three GaC phases (two cubic phases and one hexagonal phase) are first predicted. The band gaps of Fm3̅m, F4̅3m, and hexagonal GaC are 0.449, 2.733, and 3.340 eV, respectively. In particular, the band gap of F4̅3m GaC and hexagonal GaC is bigger than that of GaN. Compared to GaN semiconductors, the C-2p state is in the valence band region across the Fermi level, which is beneficial to electronic mobility and electronic transport capacity near the Fermi level. In addition, three GaC phases exhibit ultraviolet properties. The first peak of three GaC phases produces the right migration compared to the GaN semiconductor. Therefore, the author predicts that GaC is a potential third-generation semiconductor material which is potentially used in future third-generation semiconductor industries.