Hall measurements under weak persistent photoexcitation in Si-doped Al xGa1-xAs

A. Baraldi, C. Ghezzi, A. Parisini, A. Bosacchi, S. Franchi

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1 Citation (Scopus)


The low-temperature Hall mobility of photoexcited electrons has been measured in Si-doped MBE AlGaAs samples. Different fractions of occupied DX centres were obtained by selecting different free-electron densities: possible systematic errors in Hall measurements due to the method of photoexcitation are demonstrated and critically analysed. Using suitable values for the acceptor density and the alloy scattering potential a fair fitting of the experimental data was achieved within both negative-U and positive-U models for the DX centre. Discrepancies between calculated and experimental mobility versus temperature curves are observed, which are more evident the lower the free-electron densities. They are tentatively explained as being due to electrons in an impurity band originated by the shallow effective-mass state related to the Gamma minimum of the conduction band.

Original languageEnglish
Article number005
Pages (from-to)B27-B30
JournalSemiconductor Science and Technology
Issue number10 B
Publication statusPublished - Dec 1 1991

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry

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