Mid-IR Electroluminescence in Quantum Cascade Structures with GaInAs/InP Active Region

Quantum Cascade (QC) lasers are based on inter-subband transitions in the conduction band. This characteristic gives the flexibility to design the active region specifically to meet the user requirements, almost independently of the material chosen for its realization. So far, laser action has been reported in a number of different material systems, GaInAs/AlInAs both lattice matched to InP and strained, and GaAs/AlGaAs with various Al mole fractions and InGaAs interlayers. Electroluminescence from p-type QC structures was shown also in Si/SiGe multilayers. Here we present the realization of an GaInAs/InP quantum cascade electroluminescent device emitting at a wavelength of lambda ~ 10 mum. The importance of this semiconductor alloy, with respect to the usual InP-based QC lasers resides in the capability of building a completely Al-free laser both in the waveguide and in the active region.