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

Abstract

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

The values of binding energy changed from previous versions because of a better understanding for the dielectric permittivity. Also, the Gamma - X donor states are better explained

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• Valley susceptibility of an interacting two-dimensional electron system
• Two-dimensional electrons occupying multiple valleys in AlAs
• Observation of Quantum Hall Valley Skyrmions
• Modulating the growth conditions: Si as an acceptor in (110) GaAs for high mobility p-type heterostructures
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Cited by in corpus (4)

• Multivalley two-dimensional electron system in an AlAs quantum well with mobility exceeding $2\times 10^6$ cm${}^2$V${}^{-1}$s${}^{-1}$
• Design rules for modulation-doped AlAs quantum wells
• Single-valley high-mobility (110) AlAs quantum wells with anisotropic mass
• Valley degeneracy in biaxially strained aluminum arsenide quantum wells