Suppression of Dark-Line Defect Growth in AlGaAs/InGaAs Single Quantum Well Lasers Grown on Si Substrates

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Abstract
We report the suppression of dark-line defect growth in AlGaAs/In x Ga1- x As quantum well lasers on Si substrates grown by metalorganic chemical vapor deposition. An AlGaAs/In0.02Ga0.98As laser on Si with an In0.08Ga0.92As intermediate layer (InGaAs IL) has a stress-relieved active layer, while an AlGaAs/In0.07Ga0.93As laser on Si with an InGaAs IL has a compressive-stress induced active layer. The AlGaAs/In0.07Ga0.93As laser had a higher threshold current density than the AlGaAs/In0.02Ga0.98As laser due to the increased bending of the threading dislocations in the active layer. The lifetimes of these lasers at 300 K were markedly increased, due to the reduction in the dark spot density resulting from the introduction of the InGaAs IL and the reduction in the dark-line defect growth velocity resulting from the dislocation pinning in the InGaAs active layer.