Potential model of dye molecule from measurements of the photocurrent in monolayer assemblies

Abstract

A semitransparent Al layer is coated with several arachidate layers, one monolayer of quinquethienyl (mixed with arachidate), and some layers of arachidate; the arrangement is contacted with mercury. A bias voltage is applied and the photocurrent is measured as a function of the applied voltage and the temperature for different positions of the dye within the layer assembly. The photocurrent depends on the detailed assemblage, demonstrating the possibility of constructing photoelectric devices based on a planned molecular architecture. The results are in agreement with a simple theoretical model. A reasonably detailed description is obtained for the shape of the potential profile of the excited π electron of the dye responsible for the photocurrent.