On the basis of a 2-level model, a relationship was obtained between the recombination probability and the instantaneous value of the photocurrent. The spectral and relaxation dependences of the photocurrent, and the cross-section for photon capture, were used to determine the ionization energy of S-centers, the carrier lifetimes at these centers, and the dependence of the ionization energy upon the concentrations and depths of the A-centers. A spike-like relaxation of the photoconductivity and the cross-section for photon capture after photo-excitation of deep centers was explained in terms of relaxation of the cross-section for photon capture at S-centers.

L.I.Bruk, O.S.Gorya, V.A.Korotkov, L.E.Kovalev, L.V.Malikova, A.V.Simashkevich: Neorganicheskie Materialy, 1995, 31[10], 1296-8 (Inorganic Materials, 1995, 31[10], 1180-2)