Electron Spin Resonance Experiments on Donors in Silicon. I. Electronic Structure of Donors by the Electron Nuclear Double Resonance Technique

The ground-state wave function of the antimony, phosphorus, and arsenic impurities in silicon has been investigated by means of the electron nuclear double resonance (ENDOR) method. By this method the hyperfine interactions of the donor electron with the ${\mathrm{Si}}^{29}$ nuclei situated at different lattice sites were obtained. The isotropic part of the hyperfine interaction agreed with the theory of Kohn and Luttinger to better than 50%. From a comparison of the experimental results with their theory a value for the conduction band minimum in silicon of $\frac{k_0}{k_{max}}=0.85\mathrm{}\pm 0.03$ was obtained. So far no satisfactory theory exists to account quantitatively for the observed anisotropic part of the hyperfine interaction.