Adsorption of PTCDA and C60 on KBr(001): electrostatic interaction versus electronic hybridization

TL;DR

This study investigates how PTCDA and C60 molecules adsorb on KBr(001) surfaces, revealing electrostatic interactions as the dominant mechanism, which supports their potential use in molecular electronics with insulator substrates.

Contribution

The paper provides a systematic analysis combining DFT and AFM to distinguish electrostatic interactions from electronic hybridization in molecule-surface adsorption.

Findings

Electrostatics is the primary interaction mechanism for PTCDA and C60 on KBr.

Alkali-halides are suitable supports for low polarizability molecules in electronics.

DFT and AFM effectively characterize adsorption mechanisms.

Abstract

The adsorption of functional molecules on insulator surfaces is of great importance to molecular electronics. We present a systematical investigation of geometric and electronic properties of PTCDA and C60 on KBr(001) using DFT and non-contact atomic force microscopy. It was found that electrostatics is the primary interaction mechanism for PTCDA and C60 adsorbed on KBr. It was thus concluded that alkali-halides is a competitive candidate to be adopted to support low polarizability molecules, such as PTCDA, in future electronics.