Effects of strain on the electrical properties of silicon carbide

摘要

We use density functional calculations to elucidate the effects of strain on the electronic properties of 4H-SiC. Both compressive and tensile uniaxial strain result in a smaller energy gap and splitting of the conduction band valleys. Compared to compressive strain, tensile strain results in larger valley splitting and larger changes to the electron effective masses. For strain larger than 1.5%, in one hexagonal direction, the important conductivity mass can be reduced by more than 50%. For biaxial tensile strain, we also observe effective mass changes similar to the uniaxial results.