Theoretical and electron paramagnetic resonance studies of hyperfine interaction in nitrogen doped 4H and 6H SiC

Abstract

Motivated by recent experimental findings on the hyperfine signal of nitrogen donor (NC) in 4 H and 6 H SiC, we calculate the hyperfine tensors within the framework of density functional theory. We find that there is negligible hyperfine coupling with 29Si isotopes when NC resides at h site both in 4 H and 6 H SiC. We observe measurable hyperfine coupling to a single 29Si at k site in 4 H SiC and k1 site in 6 H SiC. Our calculations unravel that such 29Si hyperfine coupling does not occur at k2 site in 6 H SiC. Our findings are well corroborated by our new electron paramagnetic resonance studies in nitrogen doped 6 H SiC.