Spontaneous and stimulated emission in InAsSb-based LED heterostructures

Electroluminescence of LED heterostructures with active layer made of InAsSb films grown on InAs substrates was studied in the temperature range T = 4.2-300 K. At low temperatures (T = 4.2-100 K), stimulated emission was observed with an optical cavity formed normal to the growth plane. The emission became spontaneous at higher temperatures due to the resonant “switch-on” of the CHHS Auger recombination process in which the energy of a recombining electron-hole pair is transferred to a hole transitioning to the spin-orbit-splitted band. The spontaneous character of emission continued up to room temperature because of the influence of other Auger processes. The results obtained suggest that InAsSb-based LED heterostructures are promising for the fabrication of vertically-emitting mid-infrared lasers.