D- centers probed by resonant tunneling spectroscopy

A donor-related resonance is observed in double-barrier resonant tunneling devices with Si donors incorporated in the quantum well. In high magnetic fields the resonance becomes dominant over the Is resonance associated with the ground state of a single donor. The bias position of the donor resonance, its magnetic field dependence, and large amplitude indicate unambiguously that the resonance is due to tunneling through the ground state of a shallow donor with two bound electrons (D- level).