EXPERIMENTAL INVESTIGATIONS OF SURFACE PHOTO-CHARGE EFFECT IN DIFFERENT MATERIALS

This paper deals with some new experimental investigations, connected with so - called surface photo - charge effect. An experimental set - up for irradiating samples with white light is designed and it is used for investigating different types of materials, metals, superconducti ng, ceramics, conducting ferrites, semiconductor crystals. All of them exhibit the effect with a different response amplitude. The dependenc e of the signal amplitude on the incident light intensity for the diff erent materials is plotted graphically. An experimental investigations on the influence an the modulation frequency, polarization (in the ca se of a monochromatic source) and propagation direction of the inciden t light with respect to the sample surface is carried out.