Piezoelectric scattering limited mobility as controlled by the transverse component of the phonon wave vector in quantum layers at low temperatures

• Piezoelectric interaction is important in quantum wells of compound semiconductors.
• Traditionally phonons in 2DEG are also considered 2D with in-plane wave vector.
• Transverse component of phonon wave vector also controls the low temperature transport.
• Traditional theory assumes elastic interaction and equipartition law for phonons.
• Scattering and mobility characteristics obtained for inversion layers of GaAs&CdS.

Theory of the momentum relaxation time of the carriers and of their ohmic mobility in a quantum well in a non-degenerate compound semiconductor has been developed for interaction with piezoelectric phonons at low temperatures. The calculations have been made without taking recourse either to the Kawaji's traditional model of interaction with only the in-plane component of the phonon wave vector or to the equipartition approximation for the phonon population. The numerical results obtained for inversion layers in GaAs and CdS describe how significantly does the consideration of the transverse component of the phonon wave vector in the light of the Ridley's momentum conservation approximation or of the true phonon distribution bring in significant changes in the transport characteristics compared to what the traditional approximations predict.

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