INTRINSIC LIMITS ON CARRIER MOBILITIES IN DOUBLE-LAYER SYSTEMS

An expression for intralayer resistivity in a double-layer system due to Coulomb scattering between current carriers is derived. It is shown that Coulomb interlayer carrier-carrier interaction imposes limits on available mobilities within each layer. The limits become restrictive for small layer separations and low carrier concentrations when short -range Coulombic correlations Significantly modify interactions in the system, in particular for electron-hole double layers at temperatures corresponding to the Fermi energy. In some cases these intrinsic limi ts for the mobilities may be as low as 3 x 10(4) cm(2) V-1 s(-1) for a GaAs/GaAlAs/GaAs heterostructure system-possibly one of the reasons f or low mobilities in multilayer systems.