ABSTRACT
Arrays of vertically coupled InGaAs quantum dots in AlGaAs matrix have been used in injection lasers. Increasing the band gap of the matrix material dramatically increases the quantum dot localization energy relative to the band edge of the matrix material and to the states of the wetting layer. By using this approach we reduced the thermal population of higher energy states and thus decreased the room temperature threshold current density to 63 A/cm2
(λ=1.01 µm), and increased the differential efficiency up to 70%.
