Photoluminescence characterization of PbTe/CdTe quantum dots grown by lattice-type mismatched epitaxy

• Published in: Journal of crystal growth Vol. 301; pp. 722 - 725
• Main Authors: Koike, Kazuto, Harada, Hisashi, Itakura, Tomoyuki, Yano, Mitsuaki, Heiss, Wolfgang, Groiss, Heiko, Kaufmann, Erich, Hesser, Gunter, Schäffler, Friedrich
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2007; Elsevier
• Subjects: A1. Photoluminescence; A3. Molecular beam epitaxy; B1. Quantum dots; B2. CdTe; B2. PbTe; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Nanoscale materials and structures: fabrication and characterization; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other semiconductors; Photoluminescence; Physics; Quantum dots; Specific materials; 78.55.Hx; B2. CdTe; 78.67.Hc; A3. Molecular beam epitaxy; B2. PbTe; 81.15.Hi; 78.67.De; 65.80.+n; A1. Photoluminescence; B1. Quantum dots; Atomic force microscopy; Inorganic compounds; Interface energy; Quantum dots; Quantum wells; Photoluminescence; Lead tellurides; Transmission electron microscopy; II-VI semiconductors; Cadmium tellurides; Mismatch lattice; Growth mechanism; 81.15.Hi; 78.55.Hx; 78.67.De; 78.67.Hc; 65.80.+n; Al. Photoluminescence; A3. Molecular beam epitaxy; Bl. Quantum dots; B2. CdTe; B2. PbTe; Molecular beam epitaxy; Nanostructured materials
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2006.11.115

This paper describes molecular beam epitaxial growth and photoluminescence (PL) properties of PbTe quantum wells (QWs) and quantum dots (QDs) in CdTe matrix. Cross-sectional observation by atomic force microscopy (AFM) and high-resolution transmission electron microscopy (HRTEM) revealed that the PbTe epitaxy mode on CdTe(1 0 0) turned from a conventional two-dimensional (2D) QW-growth at 220 °C to a highly isotropic QD-growth at 280 °C by minimizing the interface energy between rocksalt PbTe and zincblende CdTe. Although both the QWs and QDs can emit mid-infrared PL, the emission from QDs was much stronger and observed even at higher temperatures over 400 K. Below 120 K, however, this intense emission from QDs became low due to the band-alignment change from type-I to type-II by the thermal mismatch between PbTe and CdTe.