Ultraviolet Photoelectron Spectroscopy (UPS) Measurements of Cyanine Dye Films Fabricated by Solution Jet Beam Deposition Method

Abstract

We report ultraviolet photoelectron spectroscopy (UPS) measurements of cyanine dye films fabricated by solution jet beam method without exposure to air. The solution jet beam method is a novel technique to fabricate organic thin films in vacuum, where solution of the organic material is sprayed in vacuum. This method can be applied to organic materials which cannot be vacuum-evaporated due to thermal decomposition, as in the case of cyanine dyes. The observed spectra were sharper than those of spin-coated films exposed to air, demonstrating the advantage of the present approach. The spectra were compared with the results of density functional theory (DFT) calculations.