NEW CONCEPT FOR THE REDUCTION OF IMPURITY SCATTERING IN REMOTELY DOPED GAAS QUANTUM-WELLS

We present a new concept to reduce impurity scattering in remotely dop ed GaAs single quantum wells by using heavy-mass X electrons in barrie rs formed by short-period AlAs/GaAs superlattices to smooth the potent ial fluctuations of the ionized Si dopants. Electron mobilities as hig h as 120 m(2)/V s and electron densities up to 1.5 x 10(16) m(-2) are obtained in 10 nm GaAs single quantum wells in the one-subband conduct ivity mode without any parallel conductance. In addition to magnetotra nsport we present voltage dependent capacitance and photoluminescence measurements as well as self-consistent calculations to demonstrate th e applicability of our concept.