HOT-ELECTRON ELECTROLUMINESCENCE IN ALGAAS/GAAS HETEROJUNCTION BIPOLAR-TRANSISTOR

When biased in the active region at high collector voltages, AlGaAs/GaAs single heterojunction bipolar transistors have been observed to emit light in the 1. 1-2.5 eV energy range. The spectral distribution of the emitted radiation results from the superimposition of (i) two peaks at about 1.4 and 2.1 eV, due to band-to-band recombination of cold electrons and holes, and (ii) a nearly exponential tail due to hot-electron-induced electroluminescence, whose intensity depends on reverse collector-base voltage. Moreover, a linear correlation has been found between the intensity of the bot-electron-induced electroluminescence and the current generated by impact ionization.