Influence of InGaAs overgrowth layer on structural and optical properties of InAs quantum dots

• Published in: Journal of crystal growth Vol. 255; no. 1; pp. 57 - 62
• Main Authors: Kim, Jin Soo, Lee, Jin Hong, Hong, Sung Ui, Han, Won Seok, Kwack, Ho-Sang, Oh, Dae Kon
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2003; Elsevier
• Subjects: A1. Energy-level spacing; A1. Quantum dot aspect ratio; A3. Quantum dots; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Molecular, atomic, ion, and chemical beam epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Physics; Quantum dots; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); 78.66.Fd; 81.15.Hi; A1. Quantum dot aspect ratio; A1. Energy-level spacing; A3. Quantum dots; 81.05.Ea; Gallium arsenides; Inorganic compounds; Quantum dots; 81.15.Hi A1. Energy-level spacing; Photoluminescence; Crystal growth from vapors; Experimental study; Fabrication property relation; Coatings; Indium arsenides; Thickness; Self-assembly; Transmission electron microscopy; Optical properties; Molecular beam epitaxy; Fabrication structure relation; Arsenides; III-V semiconductors
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(03)01210-7

Self-assembled InAs quantum dots (QDs) covered by In 0.15Ga 0.85As layer with different thickness were grown by molecular beam epitaxy and their structural and optical properties were investigated by transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. Cross-sectional TEM images showed that the shape of InAs QD, particularly the height, was controlled by changing the thickness of InGaAs overgrowth layer, thus changing the optical properties. The emission peak position of InAs QDs covered by 8.5 nm In 0.15Ga 0.85As layer was 1.30 μm at room temperature with the energy-level spacing between the ground states and the first excited states of 80 meV, which is about 1.5 times larger than that of InAs QDs capped by GaAs layer. The longer emission wavelength with relatively larger energy-level spacing was related to the QD aspect ratio (height/width) that was confirmed by TEM images.