Electrical characterization of semi-insulating devices for electrophotography

It has been shown that in semi-insulating films, the characterization of ch arge transport phenomena, such as dielectric relaxation, by resistance and capacitance only is insufficient. The independent roles played by additiona l transport parameters, including charge injection, trapping and field depe ndent mobility, are elucidated by a first principle treatment of charge tra nsports in both the closed circuit and open circuit modes. Experimental res ults from typical electrophotographic paper and charging roll samples are c ompared with the results of mathematical simulations. The advantage of open circuit measurements, such as Electrostatic Charge Decay (ECD), is noted.