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InP Self Assembled Quantum Dot Lasers Grown on GaAs Substrates by Metalorganic Chemical Vapor Deposition R. D. Dupuis1), J. H. Ryou*1), R. D. Heller1), G. Walter2), D. A. Kellogg2), N. Holonyak, Jr2), C. V. Reddy3), V. Narayanamurti3), D. T. Mathes4), and R. Hull4) 1) Microelectronics Research Center, The University of Texas at Austin 10100 Burnet Road, Building 160, Austin, TX 78758 USA Phone: +1-512-471-0537, Fax: +1-512-471-0957, e-mail: [email protected] 2) Center for Compound Semiconductor Microelectronics, The University of Illinois at UrbanaChampaign, Urbana, IL 3) Gordon McKay Laboratory of Applied Science, Harvard University, Cambridge, MA 02138 4) Department of Materials Science and Engineering, The University of Virginia, Charlottesville, VA *Now with Honeywell VCSEL Products Division, Plymouth MN 55441 ABSTRACT We describe the operation of lasers having active regions composed of InP selfassembled quantum dots embedded in In0.5Al0.3Ga0.2P grown on GaAs (100) substrates by MOCVD. InP quantum dots grown on In0.5Al0.3Ga0.2P have a high density on the order of about 1-2x10 cm-2 with a dominant size of about 10-15 nm for 7.5 ML growth.[1] These In0.5Al0.3Ga0.2P/InP quantum dots have previously been characterized by atomic-force microscopy, high-resolution transmission electron microscopy, and photoluminescence.[2] We report here the 300K operation of optically pumped red-emitting quantum dots using both double quantum-dot active regions and quantum-dot coupled with InGaP quantum-well active regions. Optically and electrically pumped 300K lasers have been obtained using this active region design; these lasers show improved operation compared to the lasers having QD-based active regions with threshold current densities as low as Jth ~ 0.5 KA/cm2 . INTRODUCTION III-phosphide self-assembled quantum-dot (SAQD or simply QD) structures having delta-functional behavior of the density of states and the discrete energy levels of carriers induced by three-dimensional quantum confinement offer the potential to realize injection lasers operating in the visible spectral region with improved performance characteristics, such as low threshold current density, high characteristic temperature, and high differential gain [3,4,5]. The direct growth of coherently strained defect-free self-assembled quantum dots on planar substrates using the coherent Stranski-Krastanow (SK) growth mode [6,7] offers the potential to develop QD visible laser devices with the theoretically predicted and experimentally realized improved performance. Also, the SAQD growth process can overcome the limitation of lattice matching between the substrate and epitaxial active region due to the intrinsic strain-compliant nature of the SK growth mode. III-As quantum dot-related structures for infrared optoelectronic applications at ? ~1.3? m have been extensively researched for growth condition optimization, material property characterization, and device applications including lasers in the infrared spectral region. Since H11.6.1

the first demonstration