Conduction-electron spin resonance in zinc-blende GaN thin films

We report electron-spin-resonance measurements on zinc-blende GaN. The observed resonance has an isotropic g value of 1.9533±0.0008 independent of temperature, a Lorentzian line shape, and a linewidth (18 G at 10 K) which depends on temperature. The spin-lattice relaxation time at 10 K was estimated to be ${\mathit{T}}_{1\mathit{e}}$=(6±2)×${10}^{\mathrm{-}5}$ sec. Using a five-band model a g value consistent with the experimental results was obtained and a conduction-electron effective mass ${\mathit{m}}^{\mathrm{*}}$/${\mathit{m}}_0$=0.15±0.01 was calculated. The observed signal, together with conductivity data, was attributed to nonlocalized electrons in a band of autodoping centers and in the conduction band.