Fluorescence of GaAs Under Intense Electron Excitation

Abstract

Fluorescent emission from Te or Zn-doped GaAs was examined under electron beam excitation sufficient to generate electron-hole pairs at rates ranging from 3×1022 to 4×1025cm−3sec−1, and over the temperature range 77° to 300°K. Peak emission frequencies were constant in this intensity range, and the spectrum from Zn-doped samples agreed qualitatively with transitions between acceptor states and a Boltzmann population in the conduction band. Te-doped samples showed strong emission at 1.494 eV. An unsuccessful attempt was made to excite coherent emission with excitation intensities exceeding 8×1025cm−3sec−1. No spectrum narrowing or shift in emission frequency was seen; this is consistent with a recombination lifetime of 6×10−10 sec or less.