Hot-Electron Spectroscopy of GaAs

We report a new technique that enabled us to measure nonequilibrium carrier transport in GaAs. Hot electrons were injected into $n^{+}$-GaAs with an excess energy of 0.25 eV above the conduction-band edge. The effect of scattering on the injected electrons was observed by use of a planar doped barrier as a "hot-electron spectrometer." The measured spectra indicated that significant scattering occurred and that mean free paths were on the order of a few hundred angstroms.