Novel direct and wide bandgap SiC semiconductors: High-throughput screening and density functional theory

Abstract

High-throughput computing has been widely used in the field of material design because of its feasibility, efficiency, accuracy and predictability. Fourteen new high-temperature SiC polymorphs were theoretically established via high-throughput screening, and density functional theory (DFT) was employed to investigate their physical properties. The new SiC polymorphs have mechanical and thermodynamic stability, and 10 of them can even maintain thermal stability at high temperatures up to 2000 K. The electronic band structure obtained by the Heyd–Scuseria–Ernzerhof (HSE06) hybrid functional shows that 13 of the new SiC polymorphs have a wide bandgap, 6 of which have a direct or quasi-direct bandgap. Notably, compared with those of 3C-SiC, the holes of I4₁/a-II SiC, I4₁/a-IV SiC, and P4/ncc-I SiC have lower effective masses in the [1 0 0] direction; in particular, the hole effective mass of P4/ncc-I SiC is only approximately 4.6 % of that of 3C-SiC. Owing to their direct wide bandgap, excellent thermal stability and low effective mass, the newly proposed SiC polymorphs have great application potential in the field of microelectronics.