A new mechanism of impurity photoconductivity in semiconductors has be
en discovered. The form of the long-wavelength photoconductivity spect
ra observed in p-GaAs0.94Sb0.06:Ge is satisfactorily explained in term
s of resonance ionization of impurity levels by phonons excited during
absorption of infrared radiation. (C) 1997 American Institute of Phys
ics.