4-11 mu m infrared emission and 300 K light emitting diodes from arsenic-rich InAs_1-xSb_xstrained layer superlattices

Arsenic-rich InAs/lnAs1-xSbx strained layer superlattices (SLSs) grown on GaAs substrates by molecular beam epitaxy (MBE) are studied for their potential application as infrared emitters. The long-wavelength emission (4-11 mu m) is highly sensitive to superlattice design parameters and is accounted for by a large type-II band offset, greater than in previously studied antimony-rich InSb/lnAs1-xSbx SLSs. High internal PL efficiencies (>10%) and intense luminescence emission were observed at these long wavelengths despite large dislocation densities. Initial unoptimized InAs/lnAs1-xSbx SLS light emitting diodes gave approximately=200 nW of lambda =5 mu m emission at 300 K.