Magneto-optical studies of free-standing hydride-vapor-phase epitaxial GaN

Abstract

Magneto-optical studies of donor excitation in hydride-vapor-phase epitaxial GaN are reported. Donor ground-to-excited state transitions are observed in the infrared for Si, O, and a third unidentified donor as a function of magnetic field to 11 T. Transitions from the ground state to ${2p}_{\ifmmode\pm\else\textpm\fi{}}$ and ${3p}_{\ifmmode\pm\else\textpm\fi{}}$ excited states are studied. Values for effective mass ground and excited state binding energies are determined from the observed excited-state separation. We find a value of $29.1\ifmmode\pm\else\textpm\fi{}0.5\mathrm{meV}$ for the effective-mass donor binding energy in GaN. Ground state binding energies for ${\mathrm{Si}}_{\mathrm{Ga}}$ and ${\mathrm{O}}_{\mathrm{N}}$ are $30.18\ifmmode\pm\else\textpm\fi{}0.1\mathrm{meV}$ and $33.20\ifmmode\pm\else\textpm\fi{}0.1\mathrm{meV},$ respectively. Separation rates for the ${2p}_{+}$ and ${2p}_{\ensuremath{-}}$ excited states with magnetic field are consistent with an electron effective mass of ${0.22m}_{0}.$