Effects of Electrode Material on Injection and Space Charge Formation in Polyimide

Space charge formation in polyimide (PI) films heavily depends upon the water content. In order to clarify the effect of carrier injection on space charge properties in PI films, space charge distributions were observed in the PI films with different electrode conditions, such as aluminium (Al) or gold (Au) deposited on the both surfaces of the PI films. In each sample, positive and negative homo space charges were observed near the respective electrodes and their distribution profiles were similar to each other. No remarkable effects of electrode materials were observed. The space charge behavior in PI films may be explained by assuming surface states and carrier traps or surface region where carrier generation takes place.