Transmission electron microscope observation of dark-spot defects in InGaAsP/InP double-heterostructure light-emitting diodes aged at high temperature

Abstract

Dark-spot defects revealed in the electroluminescence patterns of degraded InGaAsP/InP double-heterostructure light-emitting diodes that are operated at the current density of 8.0 kA/cm2 at 200 °C were investigated using transmission electron microscopy. Bar-shaped defects lying in the direction of 〈100〉 or 〈110〉 were observed corresponding to the dark defects. These defects were precipitates of a certain kind of metal or compound and not ’’dislocationlike’’ ones.