Optical and structural properties in type-II InAlAs/AlGaAs quantum dots observed by photoluminescence, X-ray diffraction and transmission electron microscopy
| Autor: | A. Ben Daly, M.A. Maaref, Valentin Craciun, E. Laura Ursu, Doina Craciun, Aristide Lemaître, Bogdan Stefan Vasile, F. Iacomi |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Photoluminescence Materials science business.industry Analytical chemistry 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics Epitaxy 01 natural sciences Reciprocal lattice Optics Lattice constant Transmission electron microscopy Quantum dot 0103 physical sciences X-ray crystallography General Materials Science Electrical and Electronic Engineering 0210 nano-technology business High-resolution transmission electron microscopy |
| Zdroj: | Superlattices and Microstructures. 110:1-9 |
| ISSN: | 0749-6036 |
| DOI: | 10.1016/j.spmi.2017.08.017 |
| Popis: | We present the effects of AlGaAs alloy composition on InAlAs quantum dots (QDs) optical and structural properties. Photoluminescence (PL) analysis of samples having a variety of aluminium composition values covering type-II transitions clearly in QDs showed the presence of two transitions X-S h and X-P h . High-resolution X-ray diffraction (HRXRD) investigations showed that the layers grew epitaxially on the GaAs substrate, with no relaxation regardless the Al content of AlGaAs layer. From the reciprocal space map (RSM) investigation around (004) and (115) diffraction peaks, it was shown that the InAlAs layer is fully strained, the in-plane lattice parameters (a and b, a = b) being identical to those of GaAs substrate, while the c lattice parameter was dependent on the In and Al concentrations, being larger than that of the substrate. High-resolution transmission electronic microscopy (HRTEM) investigations confirmed that films grew epitaxially on the GaAs substrate with no visible dislocations or other major defects within the InAlAs/GaAlAs QDs structure. |
| Databáze: | OpenAIRE |
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