Study of photoirradiation for YBa2Cu3O6+x compounds and the electron structure by positron experiment

We present positron lifetime data of YBa2Cu3O6+x(x=0.92, 0.43) compounds for different photoirradiation time. It is given that change of the local electron density and vacancy concentration with photoirradiation time. It is found that there is transform at the electronic structure of Cu-O chains. We also have discussed the effect of photoirradiations time on the electronic structure of YBa2Cu3O6+x systems and their charge reservoir layer and CuO2 plane conduction layer. The positron experimental results support the model of photoinduced oxygen-diffusion mechanism.