First-principles calculation on the concentration of intrinsic defects in 4H-SiC

Based on the first-principles pseudopotentials and the plane wave energy band method,the supercells of perfect crystal 4H-SiC and those with intrinsic defects VC,VSi,VC-C and VC-Si were calculated.Ignoring the atomic relaxations,the results show that the formation energy of intrinsic defects is ranked,from low to high,as VC,VC-C,VSi to VSi-Si at 0 K.The equilibrium concentration of each intrinsic defect can be deduced from the formation energy of each intrinsic defect.The concentration ranks,from high to low,as VC,VC-C,VSi,VSi-Si,which is in accordance with the ESR and PL results.The stabilizing process of metastable defects VSi converting to VC-C was explained by formation energy.