PbSnSeTe–PbSeTe Lattice-Matched Double-Heterostructure Lasers

Abstract

The first successful growth of PbSnSeTe–PbSeTe double heterostructure layers lattice-matched to Pb_0.8Sn_0.2Te substrate by liquid phase epitaxy is reported. PbSnSeTe–PbSeTe lattice-matched double heterostructure layers have also been grown on PbTe substrate by employing step-graded PbSeTe layers with solid compositions intermediate between the PbTe substrates and the double heterostructure layers. The lasing characteristics of the resulting laser diodes suggest that nonradiative interface recombination at PbSnSeTe–PbSeTe lattice-matched heterojunctions is negligibly small and that the temperature dependence of the laser threshold current at low temperatures is mainly determined by the doping in the active region. The lowest threshold current density for lasers with 11 cm emission wavelength has been found to be as low as 90 A/cm² at 4.2 K. Laser oscillation has been observed at temperatures as high as 165 K.