Identification and Passivation of D‐Center in 4H‐SiC: A First‐Principles Study

Abstract As a deep acceptor defect in 4H‐SiC, the D‐center related to boron impurities has attracted much attention. However, there are still some disagreements regarding the origin of the D‐center, as well as a lack of sufficient understanding of the related optical transitions and carrier capture processes. In this work, based on first‐principles calculations, the optoelectronic properties of boron‐related point defects in 4H‐SiC is systematically investigated, and the passivation of hydrogen on B C defects is also evaluated. The calculated 0/−1 transition levels of substitutional defect B C are very close to the activation energies of the D‐center observed in experiments. Furthermore, the photoluminescence (PL) peak positions and non‐radiative hole capture cross‐section of B C defects calculated are all in good agreement with the experimental values of the D‐center. This confirms that the substitutional defects B C are responsible for the D‐center in 4H‐SiC. These calculation results reveal that the hydrogen atom in 4H‐SiC prefers to combine with the B C defects and to passivate the deep acceptor level within the bandgap in 4H‐SiC by forming the B C ‐H complex. This work effectively identifies and passivates the D‐center in 4H‐SiC, providing valuable insights for improving the performance of various semiconductor materials affected by deep defects.