Optical and structural characterization of GaN/AlN quantum dots grown on Si(111)
| Autor: | Anna Vinattieri, M. Mazzoni, Giancarlo Salviati, Jean Massies, Francesca Rossi, Marcello Colocci, Nicola Armani, Miguel Angel González, Pietro Giuseppe Gucciardi, L F Sanz-Santacruz, Oscar E. Martínez, D. Alderighi |
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| Rok vydání: | 2002 |
| Předmět: |
Photoluminescence
Materials science business.industry Analytical chemistry Heterojunction Cathodoluminescence Condensed Matter Physics Characterization (materials science) law.invention Optical microscope Quantum dot law Cathode ray Optoelectronics General Materials Science Near-field scanning optical microscope LIGHT EMISSION business ALN |
| Zdroj: | Journal of physics. Condensed matter 14 (2002): 13329–13336. doi:10.1088/0953-8984/14/48/385 info:cnr-pdr/source/autori:Salviati, G.; Martinez, O.; Mazzoni, M.; Rossi, F.; Armani, N.; Gucciardi, P.; Vinattieri, A.; Alderighi, D.; Colocci, M.; Gonzalez, M.A.; Sanz-Santacruz, L.F.; Massies, J./titolo:Optical and structural characterization of GaN%2FAlN quantum dots grown on Si(111)/doi:10.1088%2F0953-8984%2F14%2F48%2F385/rivista:Journal of physics. Condensed matter (Print)/anno:2002/pagina_da:13329/pagina_a:13336/intervallo_pagine:13329–13336/volume:14 |
| ISSN: | 0953-8984 |
| Popis: | GaN/AlN-based heterostructures made from stacked GaN quantum dots (QDs) have been studied by means of the cathodoluminescence (CL), photoluminescence (PL), near-field scanning optical microscopy (NSOM) and micro-Raman techniques. The influence of the number of stacked layers (2-85) and of the different electron beam injection conditions on the main optical emissions was studied by means of CL, revealing transitions from 2.5 and 4.4 eV. Power-dependent cross-sectional CL studies revealed a large (87-180 meV) blue-shift only for the optical bands located in the 2.5 and 3.1 eV spectral range. This observation enabled us to assign a zero-dimensional character to those bands. The results were confirmed by PL and NSOM studies. Different values of the blue-shift were found for specimens with different numbers of stacked layers. This suggested the presence of different residual strains inside the structures, as confirmed by micro-Raman studies. An inhomogeneous distribution of the QD emissions was also observed both in the plane and along the growth direction. |
| Databáze: | OpenAIRE |
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