Optical selection rules for shallow donors in4H−SiCand ionization energy of the nitrogen donor at the hexagonal site

Abstract

The selection rules for transitions between the electronic levels of shallow donors in 4H-SiC in the dipole approximation are derived. The ionization energy of the shallow nitrogen donor (at hexagonal site) is determined to be $61.4\ifmmode\pm\else\textpm\fi{}0.5\mathrm{meV}$ by analyzing the photothermal ionization and infrared absorption spectra of nitrogen doped samples in the frame of model that approximates the effective-mass Hamiltonian in $4H\ensuremath{-}\mathrm{SiC}$ with Hamiltonian of cylindric symmetry (Faulkner's model).