We explored degradation in electron-beam-pumped Zn1-xCdxSe/ZnSc laser structures by combining cathodoluminescence (CL) measurements in a scanning electron microscope with transmission electron microscopy. The rate of degradation, measured ad the decrease of the emitted CL intensity under electron bombardment, depends critically on the threading dislocation density and on the strain the quantum well. Degradation occurs via the formation of dark spot defects, which are related to bombardment-induced neworks of dislocation loops in the quantum well. These degradation defects often initiate where threading dislocations cross the quantum well. We propose a self-supporting dislocation climb mechanism activated by nonradiative recombination to explain the formation and propagation of the degradation defects
Combined Transmission Electron Microscopy and Cathodoluminecence Studies of Degradation in Electron-Beam-Pumped Zn1-Xcdxse/Znse Blue-Green Lasers
Vanzetti, Lia Emanuela;
1998-01-01
Abstract
We explored degradation in electron-beam-pumped Zn1-xCdxSe/ZnSc laser structures by combining cathodoluminescence (CL) measurements in a scanning electron microscope with transmission electron microscopy. The rate of degradation, measured ad the decrease of the emitted CL intensity under electron bombardment, depends critically on the threading dislocation density and on the strain the quantum well. Degradation occurs via the formation of dark spot defects, which are related to bombardment-induced neworks of dislocation loops in the quantum well. These degradation defects often initiate where threading dislocations cross the quantum well. We propose a self-supporting dislocation climb mechanism activated by nonradiative recombination to explain the formation and propagation of the degradation defectsI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
