Rough and Fine Tuning of Metal Work Function via Chemisorbed Self-Assembled Monolayers

The sign of the monolayer-induced metal work function change is mainly determined by the relative polarizabilities of the head- and tail-groups of the molecules, while its magnitude can be finely tuned by adjusting the strength of depolarization in the SAM, which depends on the choice of length of the nonpolarizable spacer between the polar groups.