Photoconduction and photocontrolled collective phenomena in Peierls conductor TaS3

Effect of illumination on linear and nonlinear conduction of a quasi-one-dimensional conductor o-TaS 3 is studied. Evidence for the quadratic recombination is found. We demonstrate that the low-temperature conduction of TaS 3 is not provided by electrons and holes excited over the Peierls gap, whereas it is for photoconduction. Photoinduced change of the linear conduction results in appearance of long-living metastable states, substantial growth of the threshold field and increase of the low-temperature dielectric permittivity.