PHOTOCONDUCTION AND SEMICONDUCTION IN MONOCRYSTALS OF THE CHARGE-TRANSFER COMPLEX, PERYLENE–FLUORANIL

Single crystals of the perylene–fluoranil charge-transfer complex were found to be photoconductive throughout the near ultraviolet, visible, and near infrared spectral regions. The temperature dependence of the semiconduction and photoconduction are characterized by apparent activation energies of 0.73 ev and 0.12 ev, respectively. Conductivity parallel to the c-crystallographic axis (along which the complex units are stacked in columns) was found to be about threefold greater than that in the perpendicular direction. Attempts to measure carrier mobilities proved unsuccessful. The results suggest extrinsic carrier generation accompanied by pronounced carrier trapping processes.