Self-organization of organic molecules appears as one of the most promising approaches to the further miniaturization of electronic devices. However, we are only beginning to understand how the mechanisms of molecular recognition and self-assembly can be exploited for actual device production [1,2]. In this context, the adsorption of (s)-glutamic acid on Ag(110) was investigated using reflection absorption infra red spectroscopy (RAIRS) and scanning tunneling microscopy (STM) [3]. Interestingly, long-range order at very low coverages was observed resulting in the formation of correlated molecular rows. Similar findings were reported for phenylglycine and adenine adsorbed on Cu(110) [4]. Here, we study the origin of this order using density-functional theory (DFT) calculations in generalized gradient approximation (GGA). Long-range electrostatic as well as short-range covalent and steric interactions are analyzed in detail.
[1] W. G. Schmidt et al., Appl. Phys. A 85, 387 (2006).
[2] S. Blankenburg and W. G. Schmidt, Phys Rev. B 74, 155419 (2006).
[3] T. E. Jones, M. Rocca and L. Vattuone, Langmuir 21, 9468 (2005).
[4] Q. Chen and N.V. Richardson, Nat. Mater. 2, 324 (2003). |