Accession Number : AD0499901

Title :   The Dielectric Properties of Photoconducting Phosphors.

Descriptive Note : Final rept. 15 Jun 49-15 May 52,

Corporate Author : POLYTECHNIC INST OF BROOKLYN NY

Personal Author(s) : Dropkin, J. J.

Report Date : 31 MAY 1952

Pagination or Media Count : 48

Abstract : The study of the effect of intensity of illumination on the dispersion of the complex dielectric constant of a phosphor leads to the conclusion that the dielectric constant and dielectric loss of the phosphor are due to the effect of photoconducting grains separated by insulating boundaries rather than the polarizability of trapped electrons. A review of the theory of dielectric dispersion shows that these two mechanisms are equivalent to explain the experimental behavior of the phosphor but that the effect of increasing the light intensity is to decrease the grain conductivity and hence the relaxation time on one hypothesis, but can only affect relative distribution of electrons in traps on the other. The latter is rejected as inadequate to explain a ten-fold decrease in relaxation time for a four-fold increase in intensity. The complex dielectric constant and its dispersion is also studied as a function of activator concentration and temperature. These measurements are discussed from the above point of view.

Descriptors :   (*PHOSPHORESCENT MATERIALS, DIELECTRIC PROPERTIES), (*DIELECTRICS), PHOTOCONDUCTIVITY, ELECTRONS, INTENSITY, ILLUMINATION, ZINC SULFIDES, THERMAL PROPERTIES, LIGHT.

Subject Categories : Miscellaneous Materials
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE