Carrier mobility in acetophenone-soaked polyethylene estimated by transient space charge

An experiment was performed to clarify how the carrier mobility is influenced by the existence of acetophenone in polyethylene. One side of a polyethylene film, 0.1-mm thick, was soaked with acetophenone. Time-dependent charge distribution was monitored by the pulsed-electroacoustic method, when a “carrier excitation pulse voltage” was superposed on a “DC bias voltage”. It was observed that a positive charge packet was injected from the anode by the excitation pulse, and moved towards the cathode being driven by the bias voltage. There was a good correlation between local acetophenone content and the mobility at the corresponding position. It was concluded that diffusion of acetophenone leads to an increase in the mobility of the injected positive carrier, up to 3×10^-10 cm² /Vs. It was also proved that the carrier mobility can be estimated by this technique, even if the specimen has a gradation in its properties