Transmission electron microscope observation of dark defects appearing in InGaAsP/InP double heterostructure lasers aged at accelerated operation

Abstract

Transmission electron microscopy contrast analysis is presented to reveal the nature of the defects associated with the active region in degraded InGaAsP/InP double heterostructure lasers. Dislocation loops elongating in the [11̄0] direction and platelike precipitates lying in the {111} planes associated with the above dislocation loops have been observed to correspond to dark spot defects appearing in electroluminescence pattern of the lasers operated at 10-kA/cm2 current density at 250 °C junction temperature.