Mid-IR light sources with high optical power are required for many applications. We report here the mid-IR (3.8 mu m) light emission from an interband cascade (IQ LED structure with an equivalent black body emissive temperature greater than 1050 K. The IC epitaxial structure for LED comprises of 9 or IS periods of active regions separated by multilayer injection regions. We have made an 8 x 7 2D LED array with different mesa sizes. The light output as well as the efficiency increases with the increase of mesa size and the number of active/injection layers in IC LED structure. Published by Elsevier Ltd.