High optical property vertically aligned InAs quantum dot structures with GaAsSb overgrown layers

• Published in: Journal of crystal growth 2011-05, Vol.323 (1), p.164-166
• Main Authors: Liu, Wei-Sheng, Wu, Hong-Ming, Liao, Yu-Ann, Chyi, Jen-Inn, Chen, Wen-Yen, Hsu, Tzu-Min
• Format: Article
• Language: English
• Subjects: A1. Nanostructures; A3. Molecular beam epitaxy; Alignment; B2. Semiconducting III–V materials; B2. Semiconducting indium compound; Columnar structure; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Density; Exact sciences and technology; Gallium arsenide; Gallium arsenides; Indium arsenides; Materials science; Molecular structure; Nanoscale materials and structures: fabrication and characterization; 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; Optical properties of specific thin films; Other semiconductors; Physics; Quantum dots; Specific materials
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2010.10.136

This study investigates the feasibility of growing high quality columnar InAs/GaAsSb quantum dots (QDs) on a GaAs (100) substrate using a molecular beam epitaxial system. Structural and photoluminescence (PL) studies are conducted on vertically aligned, ten-period InAs quantum dot (QD) stacks with two different overgrown layer designs. Experimental results indicate an increased dot density of 5×1010cm−2 with completely suppressed coalescences in vertically aligned InAs quantum dots capped by a GaAsSb layer. This finding demonstrates a columnar dot structure with an enhanced luminescent intensity, activation energy, and narrow spectral line width of 22meV.