PHOTOCONDUCTIVITY OF PHENANTHRENE SINGLE CRYSTALS

Abstract

Single crystals of phenanthrene were grown from the melt in specially designed crystal growth tubes. Over the wavelength range studied: 200–650 nm, surface photoconductivity at room temperature is independent of photon energy >3.5 eV for applied bias fields ~10 kV cm−1. This is interpreted as saturation of the generation process for both electron and hole carriers. However, bulk photoconductivity for photon energy <3.5 eV at room temperature is dependent on photon energy and applied bias fields and generation mechanism involved in this case is attributed to exciton-exciton collisions and photoionization of excitons.