Metastable states of Si donors in AlxGa1−xAs

Abstract

Donor related states in Si-doped AlGaAs with Al compositions ranging from 0.30 to 0.59 were investigated by capacitance measurements. In addition to the stable Si-DX state, two metastable states of the silicon donor were observed. Of the two metastable states, the shallower one is attributed to the X-conduction band related effective mass state arising from substitutional silicon on the group III site. The deeper one is proposed to be related to a donor configuration different from both the substitutional configuration and that of the DX state.