Electroluminescence and lasing in type II Ga(Al)Sb/InGaAsSb heterostructures in the spectral range 3-5 mu m

We report here the study of electroluminescence and lasing in type II broke n-gap Ga(Al)Sb(As)/InGaAsSb LPE grown heterostructures containing InGaAsSb narrow-gap active layers (E-g = 0.27-0.3 eV) lattice-matched to GaSb substr ate. Strong asymmetric band offsets of the type II heterostructures were us ed to provide a good electron confinement and to increase the emission effi ciency. A strong dissimilarity observed in EL spectra of N-AlGaAsSb/InGaAsS b/P-AlGaAsSb laser structures was explained as due to different radiative r ecombination transitions. Intense room temperature spontaneous emission at lambda=4.2-4.6 mu m with optical power output of 1.5 mW and 50 mu W respect ively indicates good chance for utilization in new longwavelength LED's for ecological monitoring of gases. (C) 1999 Elsevier Science B.V. All rights reserved.