ORGANIC SEMICONDUCTORS

The dielectric, spectroscopic, and photoconductive properties of selected addition compounds and their donor and acceptor components were investigated. The study of dielectric properties entailed measurements of dielectric losses, dielectric constants, and dielectric resistivities on compressed powders. The data indicate that polarization effects caused by migrating charges are probably responsible for the high loss regions found at low frequencies. At higher frequencies bimodal temperature-dependent loss curves were found for some addition compounds. The spectral response of photoconduction in single crystals of two addition compounds and their components was measured as a function of field direction, applied voltage, light intensity, and time of illumination. The results show that space-charge build-up effects set up by travelling charge carriers dominate the conduction mechanism. The correlation of spectral response data with spectroscopic data was variable. Author