Donor binding energy and thermally activated persistent photoconductivity in high mobility (001) AlAs quantum wells

S. Dasgupta*, C. Knaak, J. Moser, M. Bichler, S. F. Roth, A. Fontcuberta I Morral, G. Abstreiter, M. Grayson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

12 Scopus citations

Abstract

A doping series of AlAs (001) quantum wells with Si δ -modulation doping on both sides reveals different dark and postillumination saturation densities, as well as temperature dependent photoconductivity. The lower dark two-dimensional electron density saturation is explained assuming deep binding energy of ΔDK =65.2 meV for Si donors in the dark. Persistent photoconductivity (PPC) is observed upon illumination, with higher saturation density indicating shallow postillumination donor binding energy. The photoconductivity is thermally activated, with 4 K illumination requiring postillumination annealing to T=30 K to saturate the PPC. Dark and postillumination doping efficiencies are reported.

Original languageEnglish (US)
Article number142120
JournalApplied Physics Letters
Volume91
Issue number14
DOIs
StatePublished - 2007

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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