PERSISTENT PHOTOCONDUCTIVITY IN INSULATING AND SUPERCONDUCTING YBA2CU3OX THIN-FILMS - TEMPERATURE AND SPECTRAL DEPENDENCE

Temperature and spectral dependencies of photoinduced changes of resis tance in YBa2Cu3Ox thin films with oxygen content ranging as 6.35 < x < 6.75 were measured on both sides of the metal-insulator transition ( MIT). The absolute value of efficiency of initiation of photoinduced c hanges decreases with an increase of oxygen content, but the position of peaks in the spectral dependence does not change with a change of x . Temperature dependencies of efficiency have an anomaly at T approxia mately 220 K, which is present in all the samples studied and correlat es with anomalies observed by other experimental techniques. Qualitati vely similar temperature and spectral dependencies of efficiency for t he samples in both the insulating and metallic phases may be considere d as an indication that the persistent photoconductivity effect in Y-B a-Cu-O on both sides of the MIT has a common origin.