Revista: | Brazilian journal of physics |
Base de datos: | PERIÓDICA |
Número de sistema: | 000403526 |
ISSN: | 0103-9733 |
Autors: | Lourenco, S.A1 Dias, I.F.L1 Duarte, J.L1 Laureto, E1 Aquino, V.M1 Harmand, J.C2 |
Institucions: | 1Universidade Estadual de Londrina, Departamento de Fisica, Londrina, Parana. Brasil 2Centre National de la Recherche Scientifique, Laboratoire de Photonique et de Nanostructures, Marcoussis, Essonne. Francia |
Any: | 2007 |
Període: | Dic |
Volum: | 37 |
Número: | 4 |
Paginació: | 1212-1219 |
País: | Brasil |
Idioma: | Inglés |
Tipo de documento: | Artículo |
Enfoque: | Analítico |
Resumen en inglés | The mechanism for low-temperature photoluminescence (PL) emissions in GaAsSb/AlGaAs and GaAsSbN/GaAs strained-layer single quantum wells (SQWs), grown by molecular-beam epitaxy, is studied in detail, using PL spectroscopy as a function of temperature and excitation intensity. In all samples, the PL peak energy as well as the full width at half maximum (FWHM), as a function of temperature, present anomalous behaviors, i.e., the PL peak energy shows a successive red/blue/redshift (S-shaped behavior) and the FWHM shows a successive blue/red/blueshift (“inverted S-shaped curve”) with increasing temperature. At sufficiently low excitation intensity and in a narrow temperature interval (50 – 80 K), the nitrogen-containing samples present two clear competitive PL peaks. The low-energy PL mechanism (8 – 80 K) is dominated by localized PL transitions, while the high-energy PL mechanism is dominated by the ground state (e1-hh1) PL transition. Additionally, these PL peaks show different temperature dependence with the low-energy PL peak, showing a stronger redshift than the high-energy PL peak. A competition process between localized and delocalized excitons is used to discuss these PL properties |
Disciplines | Física y astronomía |
Paraules clau: | Física de materia condensada, Ingeniería de materiales, Semiconductores, Pozos cuánticos, Fotoluminiscencia |
Keyword: | Physics and astronomy, Condensed matter physics, Materials engineering, Semiconductors, Quantum wells, Photoluminescence |
Text complet: | Texto completo (Ver PDF) |