Search

We have measured the hot-electron luminescence of GaAs HEMT devices over a broad spectral range in the infrared (0.4-1.4 eV). The emission intensity has spectral features suggesting that k-conserving, interconduction-band transitions dominate the emission process. The interpretation of emission spectra in terms of a hot-carrier distribution requires consideration of band-structure effects. In general this tends to reduce values of electron temperature Tel determined by the exponential fit to the experiment.

The authors measure the spectrum of radiative emission from a high quality HEMT device and relate this to the energy distribution of the channel electrons. The discussion focuses on the intraband and interband contributions to the spectrum. The intraband, bremsstrahlung component gives evidence for very energetic electrons (Tel approximately=6000 K). The radiative recombination of carriers, however, is characterized by a very much lower temperature.