The effects of defects on the defect formation energy, electronic band structure, and electron mobility in 4H–SiC

With the first-principle method, we studied the effects of the type and position of defects on the defect formation energy, electronic band structure, and electron mobility of the 4-layer hexagonal system silicon carbon (4H–SiC). The vacancy defect formation energy is smaller than the interstitial defect formation energy. The C vacancy defect formation energy is the smallest, while the Si interstitial defect formation energy is the largest. The defect formation energy is little affected by the defect position. The electronic band structure shows semi-metallic property due to the vacancy defect and the interstitial defect, and it shows a smaller bandgap due to the antisite defect. The electronic band structure changes little while the defect position changes. The electron mobility is reduced in varying degrees according to different defect types. The electron mobility changes little while the defect position changes.