Published online by Cambridge University Press: 25 February 2011
Spin dependent photoconductivity measurements provide evidence for the existence of tunneling transitions from localized tail states into the dangling bond recombination centers. These processes can be included approximately into the conventional model based on rate equations. Satisfactory values for the activation energy of the photoconductivity at low temperatures are obtained. Our model produces thermal quenching and an enhancement of the photoconductivity with rising dark Fermi level.