MBE GROWTH OF GAINASSB/ALGAASSB DOUBLE HETEROSTRUCTURES FOR INFRARED DIODE-LASERS

For the fabrication of diode lasers emitting near 2.3-mu-m, molecular beam epitaxy has been used to grow double heterostructures consisting of a Ga0.84In0.16As0.14Sb0.86 active layer and Al0.50Ga0.50As0.04Sb0.96 confining layers lattice matched to a GaSb substrate. Because the sticking coefficient is much greater for Sb than for As, high concentrations of Sb can be incorporated into the alloy layers even though the As flux during growth is much greater than both the Sb flux and the total group III flux. The n- and p-type dopant sources were GaTe and Be, respectively. The lasers have threshold current densities as low as 1.5 kA cm-2, differential quantum efficiencies as high as 50%, and pulsed output power as high as 900 mW per facet.