Temperature-dependent photoluminescence spectra of GaAsSb/AlGaAs and GaAsSbN/GaAs single quantum wells under different excitation intensities

AUTOR(ES)

Lourenço, S. A., Dias, I. F. L., Duarte, J. L., Laureto, E., Aquino, V. M., Harmand, J. C.

FONTE

Brazilian Journal of Physics

DATA DE PUBLICAÇÃO

2007-12

RESUMO

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.

Documentos Relacionados

• Photoluminescence properties of Te doped AlGaAsSb alloys
• Magnetotransport in Al xGa x-1As quantum wells with different potential shapes
• Electronic states in n-type GaAs delta-doped quantum wells under hydrostatic pressure
• Optical studies of the correlation between interface disorder and the photoluminescence line shape in GaAs/InGaP quantum wells
• Yersinia intermedia: temperature-dependent bacteriocin production.