Please use this identifier to cite or link to this item:
- Theoretical and experimental study of the excitonic binding energy in GaAs/AlGaAs single and coupled double quantum wells
- Universidade Estadual Paulista (UNESP)
- Universidade Federal de São Carlos (UFSCar)
- Universidade Estadual de Londrina (UEL)
- Universidade Federal de Minas Gerais (UFMG)
- Universidade de São Paulo (USP)
- This paper discusses the theoretical and experimental results obtained for the excitonic binding energy (Eb) in a set of single and coupled double quantum wells (SQWs and CDQWs) of GaAs/AlGaAs with different Al concentrations (Al%) and inter-well barrier thicknesses. To obtain the theoretical Eb the method proposed by Mathieu, Lefebvre and Christol (MLC) was used, which is based on the idea of fractional-dimension space, together with the approach proposed by Zhao et al., which extends the MLC method for application in CDQWs. Through magnetophotoluminescence (MPL) measurements performed at 4 K with magnetic fields ranging from 0 T to 12 T, the diamagnetic shift curves were plotted and adjusted using two expressions: one appropriate to fit the curve in the range of low intensity fields and another for the range of high intensity fields, providing the experimental Eb values. The effects of increasing the Al% and the inter-well barrier thickness on E b are discussed. The Eb reduction when going from the SQW to the CDQW with 5 Å inter-well barrier is clearly observed experimentally for 35% Al concentration and this trend can be noticed even for concentrations as low as 25% and 15%, although the Eb variations in these latter cases are within the error bars. As the Zhao's approach is unable to describe this effect, the wave functions and the probability densities for electrons and holes were calculated, allowing us to explain this effect as being due to a decrease in the spatial superposition of the wave functions caused by the thin inter-well barrier. © 2013 Elsevier B.V.
- Journal of Luminescence, v. 144, p. 98-104.
- Coupled double quantum wells
- Excitonic binding energy
- Double quantum well
- Electrons and holes
- Excitonic binding
- High-intensity fields
- Probability densities
- Theoretical and experimental
- Binding energy
- Wave functions
- Semiconductor quantum wells
- Acesso restrito
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.