Controlling C60 Organization through Dipole-Induced Band Alignment at Self-Assembled Monolayer Interfaces

Abstract

Understanding the structural organization and growth of organic molecules on self-assembled monolayers (SAMs) is crucial for creating high-performance SAM-based electronic devices. We report herein C60 adsorption onto benzenethiol (BT), pentafluorobenzenethiol (PFBT), and octanethiol (C8SH) SAM-modified Au(111) studied using scanning tunneling microscopy at the liquid–solid interface. A continuous film of C60 molecules forms at a much faster rate (k = 3.3 × 10–7 s–1) on PFBT compared to that on BT (k = 7.2 × 10–9 s–1) and C8SH SAMs (k = 9.5 × 10–9 s–1). On the basis of density functional theory calculations, we propose that the difference in C60 growth behavior originates from the dipole-induced dipole interactions between the SAM and C60. This may be further augmented by an inverse charge transfer from C60 to SAM. This work provides new insights into the self-assembly behavior of next-generation electronic materials.