Oscillatory Magneto-Absorption of the Direct Transition in Germanium

Abstract

Infrared transmission of intrinsic germanium was examined at wavelengths from 1.4\ensuremath{\mu} to 1.6\ensuremath{\mu} in constant magnetic fields up to 36 000 gauss. The magneto-absorption showed oscillatory behavior at photon energies greater than that of the direct transition. The energy gap of the direct transition was determined experimentally to be 0.803\ifmmode\pm\else\textpm\fi{}0.001 ev at room temperature. The effective mass of the electron in the ${\ensuremath{\Gamma}}_{{2}^{\ensuremath{-}}}$ conduction band was found to be $\ensuremath{\approx}0.042{m}_{0}$. Anisotropy of the oscillations was observed as a function of the orientation of the sample in the magnetic field.