Polatity-Reversal Current Ttansients in Cellulose Acetate Films

Polarity-reversal transient currents in cellulose acetate films have been studied as a function of field, thickness, and temperature. The current peaks have been observed in the current-time characteristics and these peaks may be attributed to space charge injection from electrodes. The dependence of the transient current on thickness (Iαd-3) of the sample justifies the existence of SCLC. The carrier mobility ≃(8.5±0.05)x 10-1° cm2V-1s-1 has been estimated at room temperature. The mobility in iodine-doped (2% wt/wt) sample has been found to be ≃9. 5x10-8 Cm2V-1s-1. The sign of the injected carriers is determined by using a blocking electrode method.