Study of defects in a rapidly degraded InGaAsP/InGaP double-heterostructure laser grown by liquid phase epitaxy

Abstract

A rapidly degraded InGaAsP/InGaP double-heterostructure laser (λ=810 nm) grown on a (001) oriented GaAs substrate during cw operation at room temperature, is investigated by photoluminescence topography and transmission electron microscopy. Several 〈100〉 dark-line defects and 〈110〉 dark-line defects parallel to the stripe are observed in the photoluminescence image of the active region. The 〈100〉 dark-line defects are associated with classic interstitial type dislocation dipoles with Burgers vectors of the type a/2[101] 45° inclined to the junction plane. The 〈110〉 dark-line defect corresponds to a half-dislocation loop (b̄=a/2〈011〉) with many jogs (due to climb motion). In InGaAsP/InGaP material on GaAs, it is suggested that recombination enhanced defect motion (climb motion) can occur.