Detecting spatially localized excitons in InGaN quantum well structures with a micro-photoluminescence technique

• Published in: Solid state communications Vol. 138; no. 12; pp. 590 - 593
• Main Authors: Gotoh, H., Akasaka, T., Tawara, T., Kobayashi, Y., Makimoto, T., Nakano, H.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.06.2006; Elsevier
• Subjects: A. Nitride semiconductors; Condensed matter: electronic structure, electrical, magnetic, and optical properties; D. Localized excitons; D. Optical properties; D. Sharp photoluminescence; Exact sciences and technology; 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 wells; 78.55.Cr; D. Localized excitons; 71.35.−y; D. Sharp photoluminescence; A. Nitride semiconductors; 78.67.De; D. Optical properties; A. Nitride semiconductors; D. Localized excitons; D. Optical properties; D. Sharp photoluminescence; Semiconductor materials; Gallium nitrides; Quantum dots; Quantum wells; Photoluminescence; Line widths; Nanolithography; Optical properties; Chemical composition; Indium nitrides; Spatial resolution; 78.67.De; 71.35.-y; 78.55.Cr; Localized exciton
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2006.04.006

Spatially localized excitons are observed in InGaN quantum well structures at 4 K by using a micro-photoluminescence (PL) technique. By combining PL and nano-lithographic techniques, we are able to detect PL signals with a 0.2 μm spatial resolution. A sharp PL line (linewidth of <0.4 meV) is clearly obtained, which originates from a single localized exciton induced by a quantum dot like a local potential minimum position. Sharp PL spectra detected in three QWs with different indium compositions confirm that there are exciton localization effects in quantum wells in the blue-green (about 2.60 eV, 477 nm) to purple (about 3.05 eV, 406 nm) regions.