Photoconductivity of Highly Disordered Carbon Fibers

ABSTRACTA highly disordered carbon material, activated carbon fibers, is investigated through bulk conductivity and photoconductivity measurements. This material has a high density of defect states introduced by an aqtivation process that leads to a huge specific surface area of up to 2000m2/g. The conductivity increases by a factor of 4–10 with increasing temperaturefrom 30K to 290K. In contrast, the photoconductivity decreases by a factor of three with increasing temperature. The relaxation time of the photoconductivity is rather long(on the order 10−1 sec), indicating that the recombination process proceeds through localized states. flopping processes are used to interpret the transport properties of this material.