Transition from two-dimensional to three-dimensional electroabsorption in extremely shallow quantum wells

X Chen, D W E Allsopp, W Batty

Research output: Contribution to journalArticle

Abstract

Calculations of electroabsorption in extremely shallow quantum wells are performed, accurately incorporating mixing of different subband pairs due to the Coulombic interaction. As the AlAs mole fraction is varied in the barriers of a 100 A wide AlxGa1-xAs/GaAs square quantum well, a transition from red to blueshift of the absorption edge with applied electric field occurs at x similar to 0.003. In a 20 Angstrom wide square well, which more strongly confines the excitons, the redshift of the absorption edge is still observable at low electric field strength in the simulated absorption spectra, even for AlAs mole fractions as low as similar to0.001. However, on increasing the strength of the applied electric field the blueshift becomes apparent. It is demonstrated that inclusion of Coulombic coupling between different subband pairs, particularly between confined states and quasi-continuum states, is essential for a correct prediction of the absorption edge behaviour in extremely shallow quantum wells.
Original languageEnglish
Pages (from-to)263-269
Number of pages7
JournalSemiconductor Science and Technology
Volume19
Issue number2
Publication statusPublished - 2004

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Semiconductor quantum wells
Electric fields
quantum wells
electric fields
square wells
electric field strength
Excitons
Absorption spectra
excitons
inclusions
continuums
absorption spectra
predictions
interactions
gallium arsenide
LDS 751

Cite this

Transition from two-dimensional to three-dimensional electroabsorption in extremely shallow quantum wells. / Chen, X; Allsopp, D W E; Batty, W.

In: Semiconductor Science and Technology, Vol. 19, No. 2, 2004, p. 263-269.

Research output: Contribution to journalArticle

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