We report the molecular beam epitaxial growth of InSb quantum dots (QD) inserted as sub-monolayers in an InAs matrix and grown using Sb2 and As2 fluxes. These InSb QD nanostructures exhibit intense mid-infrared photoluminescence up to room temperature. The nominal thickness of the sub-monolayer insertions can be controlled by the growth temperature (TGr = 450-320 °C) which gives rise to the variation of the emission wavelength within the 3.6-4.0 μm range at room temperature. Light emitting diodes where fabricated using ten InSb QD sheets and were found to exhibit bright electroluminescence with a single peak at 3.8 μm at room temperature. A comparative analysis of the optical properties of the structures grown using (Sb2,As2) and (Sb4,As4) is also presented