GaAs-based long-wavelength InAs quantum dots on multi-step-graded InGaAs metamorphic buffer grown by molecular beam epitaxy

摘要

Molecular beam epitaxy growth of GaAs-based long-wavelength metamorphic InAs/InGaAs quantum dots (QDs) is investigated. With optimized multi-step-graded InGaAs metamorphic buffer layers and growth conditions, room temperature 1.46 νm emission from InAs/In_(0.15)Ga_(0.85)As QDs is realized, and broad-area laser diodes are fabricated with a very low etch pit defect density of less than 5.0 × 10~3 cm~(-2). The lasers operate under pulsed operation mode at room temperature with a low threshold current density of 146.7 A cm~(-2).