Electroluminescence of InAsSb-based mid-infrared LEDs in 4.2–300 K temperature range

Abstract

Abstract. Electroluminescence of mid-infrared LEDs with active layer made of InAs andInAsSb in a wide temperature range (4.2-300 K) was studied. At low temperatures (T=4.2-100 K), stimulated emission from the LEDs was observed. The emission became spontaneous at higher temperatures due to the effect of CHHS Auger recombination process, when the energy of a recombining electron-hole pair was transferred to another hole with the latter transitioning to the spin-orbit-splitted band. The spontaneous character of recombination held up to the room temperature due to the effect of other Auger processes. Still, th e results obtained show that structures based on InAsSb are a promising material for fabrication of mid-infrared lasers. IntroductionThe mid-infrared wavelength range (MWIR, wavelengths 2-6 µm) represents great interest for the development of optoelectronic devices with applications in optical gas sensing, environmental control, biomedical imaging, thermal imaging, etc. From the viewpoint of se nsor technology, light-emitting diodes (LEDs) represent an almos t ideal source of MWIR radiation, as they de monstrate reasonably wide emission band, room temperature operation, very high modulation rate, small size and low power consumption [1]. Their pr oblem is low em issivity, which is mostly due to the spe cifics of the electronic structure of narrow-bandgap AIIIBV semiconductors, which ser ve as a ba sis for MWI R LED heterostructures. To enhance the efficiency of optoelectronic devices, it is important to understand a nd control the processes of carrier recombination, which gover n emission of light (or the la ck of thereof). For that task, it is worth studying the operation of the devices not only at working temperatures, but also at lower temperatures. Within the frames of such an approach, we have studied electroluminescence (EL) of InAsSb-based LEDs in a temperature range, 4.2-300 K.