Infrared spectra of new acceptor levels in indium- or aluminum-doped silicon

Abstract

Infrared absorption measurements have verified the existence of shallower acceptor levels associated with both indium and aluminum in silicon. The new spectra correspond to effective‐mass‐like acceptors with optical ionization energies of 112.8±0.3 meV in indium‐doped silicon and 56.3±0.3 meV in aluminum‐doped silicon. The existence of the shallower acceptor level in aluminum‐doped silicon has been further verified by Hall coefficient measurements.