Atomic-scale contrast formation in AFM images on molecular systems

Abstract

Imaging individual molecules with atomic resolution is now possible using non-contact atomic force microscopy (AFM). In all cases where atomic resolution imaging of molecules was demonstrated, chemically passivated tips were used. This chapter will discuss the factors influencing the atomic scale imaging of molecular systems. We will first discuss the effect of the tip passivation on the atomic scale contrast. Subsequently, we will consider the factors affecting the quantitative details of the apparent atomic positions (background from the neighbouring atoms, flexibility of the tip apex and non-planar samples). Finally, we will discuss how the tip flexibility affects the appearance of the inter-and intramolecular bonds imaged with AFM.