Work function of gold surfaces modified using substituted benzenethiols: Reaction time dependence and thermal stability

Abstract

The work function of Au surfaces modified with various substituted benzenethiols has been systematically investigated for application to the design of organic electronic devices. The work function was found to vary in the range of 4.37 to 5.48 eV depending on the substituted benzenethiol used, which included pentafluorobenzenethiol, 4-fluorobenzenethiol, 4-methylbenzenethiol, 4-aminobenzenethiol, and 4-(dimethylamino)benzenethiol. Subsequent thermal annealing of the modified Au films above 373 K changed the work function back to that of an unmodified Au surface. Meanwhile, thermal desorption spectroscopy revealed species desorbing from the modified Au surfaces, indicating cleavage of the C–S bond as well as the S–Au bond.