A multimechanism model for photon generation by silicon junctions in avalanche breakdown

Light emission from three device types ((1) commercial silicon JFETs, (2) bipolar transistors, and (3) a custom diode) with p-n junctions biased in controlled avalanche breakdown, has been measured over the photon energy range 1.4-3.4 eV, Previously published models are compared with these data to elucidate the mechanisms responsible for avalanche light emission in silicon. A multimechanism model fitting measured spectra and spectra measured by other researchers is presented and justified. The success of the model indicates that indirect recombination of electrons and holes is the dominant emission mechanism below the light intensity peak (/spl sim/1.8-2.0 eV), that indirect intraband recombination dominates at intermediate energies up to /spl sim/2.3 eV, and that direct interband recombination between high-field populations of carriers near k=0 dominates above /spl sim/2.3 eV. For junctions with overlayer passivation, an interference model must be applied to model measured spectra.