Electroluminescent (EL) properties of asymmetrical InAs/InAs1-ySby/InAsSbP heterostructures with the y = 0.09 and y = 0.11 InSb content in the active layer were studied in wide temperature range T = 4.2–300 K. The stimulated emission in the spectral range 4.1–4.2 µm has been observed at low temperatures (T < 30 K). It was estimated that EL spectra were formed owing to different channels of radiative recombination depending on the ambient temperature. The influence of the quality of the type II InAsSb/InAsSbP heterojunction on radiative recombination transitions has been considered.