modulation-doped Al x Ga 1x As/GaAs/Al x Ga 1 x As quantum well

We theoretically study the influence of spacer layer thickness fluctuation (SLTF) on the mobility of a twodimensional electron gas (2DEG) in the modulation-doped AlxGa1 xAs/GaAs/AlxGa1 xAs quantum well. The dependence of the mobility limited by SLTF scattering on spacer layer thickness and donor density are obtained. The results show that SLTF scattering is an important scattering mechanism for the quantum well structure with a thick well layer.