AB Initio SCF Calculations of the Carbazole and 2,4,7 Trinitro-9-Fluorenone (TNF) Molecules

Abstract

Our interest in these calculations is based on our desire to understand the properties of a photosensitive polymer. The organic polymer film consisting of a 1:1 monomer molar ratio mixture of poly-n-vinylcarbazole (PVC_Z) and 2,4,7-trinitrofluorenone (TNF) is a sensitive organic photoconductor currently being used in the IBM electrophotographic copier. In this laboratory we are presently investigating the electrical and optical properties of this and related materials. The carbazole monomer unit and the TNF molecule (see Figs. 1 and 2) are known to form charge transfer complexes about which relatively little is known. But these molecules are mainly responsible for the photosensitivity in the visible region. Our experimental results indicate that optical absorption, photo-generation efficiency of free carriers, and the very small charge carrier mobilities are all strongly field dependent. These results support the description of these materials as disordered molecular solids and we expect that the properties of the basic molecular constituents can be expected to have a relatively direct correlation to the properties of the solid as a whole.