INTERSUBBAND-COUPLING AND SCREENING EFFECTS ON THE ELECTRON-TRANSPORTIN A QUASI-2-DIMENSIONAL S-DOPED SEMICONDUCTOR SYSTEM

The effects due to intersubband coupling and screening on the ionized impurity scattering are studied for a quasi-two-dimensional electron s ystem in delta-doped semiconductors. We found that intersubband coupli ng plays an essential role in describing the screening properties and the effect of ionized impurity scattering on the mobility in a multisu bband system. At the onset of the occupation of a higher subband, the screening due to the intersubband coupling leads to a reduction of the small angle scattering rate in the lower subband. We showed that such an effect is significant in a delta-doped quantum well and results in a pronounced increase of the quantum mobility at the onset of the occ upation of a higher subband. (C) 1996 American Institute of Physics.