Interface roughness scattering limited mobility in AlAs/GaAs, Al_0.3Ga_0.7As/GaAs and Ga_0.5In_0.5P/GaAs quantum wells

Abstract

The theory of electron mobility is developed for the Gaussian eigenvalue, exponential eigenvalue, Gaussian wavefunction and the exponential wavefunction models of interface roughness scattering. Experimental results for AlAs/GaAs, Al_0.3Ga_0.7As/GaAs and Ga_0.5In_0.5P/GaAs quantum wells are examined using the four models of scattering. It is found that results for the AlAs/GaAs wells may be explained by using the eigenvalue Gaussian or the eigenvalue exponential models by choosing properly the asperity heights. The mobility values for the Al_0.3Ga_0.7As/GaAs wells may be fitted by all the models by choosing the asperity height, except for the wavefunction model when the well layer extends into the barrier layer. Results for the Ga_0.5In_0.5P/GaAs wells may be explained by all the models but the required values of asperity height are different for the wavefunction models in the case of the barrier layer extending into the well layer.