Stable Structures of Donor-Acceptor-Donor Trimer Codopants in 4H-SiC

摘要

The total energies of 4H-SiC with donor-acceptor-donor (D_2A) trimer codopants (D = N, P, As, and Sb, A = B, Al, Ga, and In), the formation energies of D_2A, DA, D, and A species and the binding energies were studied using ab initio calculations in order to determine the stable structures of D_2A trimer codopants in 4H-SiC. The results of the calculations indicated that some of the trimer codopants were formed and were stable in 4H-SiC. In particular, N_2Al, N_2Ga and N_2In trimer codopants with N(C_h)-Al/Ga/In(Si_k)-N(C_h) configuration and As_2B trimer codopants with As(Si_h)-B(C_k)-As(Si_h) configuration stably exist in 4H-SiC under the doping condition wherein the concentration ratio of donors to acceptors is 2 : 1.