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Power density and temperature dependent multi-excited states in InAs/GaAs quantum dots

Bouzaiene, L. and Sfaxi, L. and Baira, M. and Maaref, H. and Bru-Chevallier, C. (2011) Power density and temperature dependent multi-excited states in InAs/GaAs quantum dots. Journal of Nanoparticle Research, 13 (1). pp. 257-262.

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Official URL: http://www.springerlink.com/content/763j8777136m27...

Abstract

Self-assembled InAs/GaAs (001) quantum dots (QDs) were grown by molecular beam epitaxy using ultra low-growth rate. A typical dot diameter of around 28 ± 2 nm and a typical height of 5 ± 1 nm are observed based on atomic force microscopy image. The photoluminescence (PL) spectra, their power and temperature dependences have been studied for ground (GS) and three excited states (1-€“3ES) in InAs QDs. By changing the excitation power density, we can significantly influence the distribution of excitons within the QD ensemble. The PL peak energy positions of GS and ES emissions bands depend on an excitation light power. With increasing excitation power, the GS emission energy was red-shifted, while the 1-3ES emission energies were blue-shifted. It is found that the full width at half maximum of the PL spectra has unusual relationship with increasing temperature from 9 to 300 K. The temperature dependence of QD PL spectra shown the existence of two stages of PL thermal quenching and two distinct activation energies corresponding to the temperature ranges I (9-€“100 K) and II (100-300 K).

Item Type:Article
Subjects:Physical Science > Nanophysics
Divisions:Faculty of Engineering, Science and Mathematics > School of Physics
ID Code:10559
Deposited By:JNCASR
Deposited On:04 May 2011 07:17
Last Modified:04 May 2011 07:18

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