InAs/AlSb quantum-cascade light-emitting devices in the 3-5 mu m wavelength region

Midinfrared (3.7-5.3 mum) electroluminescent devices based on a quantum-cas cade (QC) design have been demonstrated using InAs/AlSb heterostructures, g rown on GaSb substrates. The very high conduction band discontinuity (>2 eV ) of this material system allows the design of QC devices at very short wav elengths. Well-resolved luminescence peaks were observed up to 300 K, with a full-width-at-half-maximum to peak wavelength ratio (Delta lambda/lambda) of the order of 8%. The emission wavelengths are in good agreement with th e results of our model. The emitted optical power is lower than that predic ted, due to a nonoptimized electron injection into the active region. (C) 2 001 American Institute of Physics.