Luminescence Due to High-Density Electron-Hole Plasma in GaAs

Abstract

Spontaneous and stimulated emissions due to high-density metallic plasma state of electrons and holes have been observed in GaAs under intense optical excitation. The experiment has been performed on high-purity epitaxial layers in the 4.2–17 K temperature range using a pulsed nitrogen laser and a dye laser as exciting sources, Luminescence band shape fits well with that calculated by taking account of the band-gap reduction and energy broadening. Dependence of the emission spectra on excitation intensity, temperature, and applied electric and magnetic fields gives support to the above interpretation. The energetics and thermodynamical properties of the high-density plasma state are discussed.