Theoretical investigation of shallow acceptors confined in Si/Si1−xGex quantum well structures

Abstract

Energy levels of the shallow acceptor states have been calculated for center-doped Si/Si1−xGex/Si quantum wells. The impurity states were calculated using an effective-mass theory that accounts for valence-band mixing as well as the mismatch of band parameters and dielectric constants between well and barrier materials. Acceptor binding energies and splitting between the acceptor 1S3/2(Γ7) and 1S3/2(Γ6) ground states were studied at various Ge concentrations and well widths. The results are discussed in comparison with the recent conclusion from the lateral transport measurements in boron-doped Si/SiGe quantum wells.