2006-004 – Dense Stacked and Strain-Compensated Quantum Dot Active Regions

Background Quantum dots (QDs) continue to intrigue technologists with the potential benefits of zero-dimensionality, low threshold current density and temperature sensitivity in modern semiconductor laser applications. Quantum dots formed by strain-driven processes are especially interesting since they can be easily embedded in a solid-state region to enable current injection and electrical/optical confinement. However, such devices often have low ground state modal gain. This gain can be increased by stacking the QD active regions, but the disadvantage is that a vertical strain field grows with each subsequent stacked QD active region. Increasing interlayer separation is a possible solution to the problem, although this reduces the overlap between the stacked QD active regions and the optical mode of the active device. There is a need for a stacked QD active structure with increased overlaps between the stacked QD active regions and the optical mode of the active device. Technology Description This technology provides a quantum dot active structure with strain-compensation regions that eliminate the compressive strain of adjacent quantum dot active regions, which allows dense stacking that increases the overlaps between the QD active regions and the optical mode of the device. The optical modal gain for semiconductor light emitting devices can therefore be increased. Andrew Roerick aroerick@innovations.unm.edu 505-277-0608