Interband cascade light emitting diodes in the 5–8 μm spectrum region

Interband cascade electroluminescence in the 5–8 μm spectrum region is observed from a staircase of Sb-based type-II quantum well structures. The structure was grown by molecular beam epitaxy on a GaSb substrate and comprises 15 periods of active regions separated by digitally graded multilayer injection regions. The device has been operated at 300 and 77 K with an output optical power up to 700 nW. The strong blue shift of the electroluminescent peak with the applied bias due to the Stark effect has also been observed.