Multi-charged acceptor centers in p-doped Si/Si 1− xGe x/Si quantum wells in the presence of a magnetic field

Abstract

Neutral (A 0) and positively charged (A +) shallow acceptor centers in p-doped SiGe/Si nanostructures are investigated in the presence of an external magnetic field. The band mixing of valence states, the confinement potential and the magnetic field are responsible for an increase in the binding energy of the system. The properties of the lower-energy states of the A + are studied and their binding energies calculated for a Si 0.87Ge 0.13 quantum well. It is shown that the ground state of the A + complex has a singlet-like parity configuration up to magnetic fields as high as 12 T. The effects of hole–hole repulsive interaction and hole–impurity attractive potential on the A + spectra are considered.