PREPARATION AND CHARACTERIZATION OF 3,4,9,10-PERYLENETETRACARBOXYLIC DIANHYDRIDE (PTCDA) FILMS DEPOSITED BY ORGANIC MOLECULAR-BEAM DEPOSITION METHOD

The optical and structural properties for 3,4,9,10-perylenetetracarbox ylic dianhydride (PTCDA) films deposited on Au-coated substrates at th e various growth temperatures by the organic molecular beam deposition (OMBD) method have been studied. The planar PTCDA molecules were orie nted almost parallel to the substrate surface in the films deposited a t the growth temperature of -160 degrees C. Orientational disorder of the molecular planes occurred especially in the films grown at higher substrate temperatures. These films had basically large anisotropy of refractive indices which were evaluated by the prism attenuated total- reflection (ATR) method. The anisotropy of indices decreased for the f ilm grown at the substrate temperature of 100 degrees C. The optical a nisotropy has been understood in terms of the molecular orientation.