X-Ray Photoconductivity of Anthracene

Abstract

The excess currents generated in anthracene crystals under x radiation have been measured as a function of x-ray intensity, electric field, and temperature. The currents were linear with respect to absorbed dose rate and electric field. A sensitivity of 7.1±0.7×10−12 C/cm2·rad at a field strength of 630 V/cm was obtained. The mobility, lifetime product, μτ, was 9.9±0.9×10−8 cm2/V. The photocurrent was observed to increase with increasing temperature and exhibited two different activation energies, one below 250°K and a second above 250°K. The magnitude of these energies decreased with increasing dose rate. The temperature behavior may be explained in terms of exciton theory or may be due to changes in carrier mobility.