The role played by the molecular geometry on the electronic transport through nanometric organic films

Author(s)

Lima, Matheus P. ^[1] ; Miwa, R. H. ^[2] ; Fazzio, A. ^[3]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Phys, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Fed Uberlandia, Inst Fis, BR-38400902 Uberlandia, MG - Brazil

^[3] Brazilian Nanotechnol Natl Lab LNNano CNPEM, POB 6192, BR-13083970 Campinas, SP - Brazil

• Document type: Journal article
• Source: Physical Chemistry Chemical Physics; v. 21, n. 44, p. 24584-24591, NOV 28 2019.
• Web of Science Citations: 0

Abstract

The electronic transport properties in molecular heterojunctions are intimately connected with the molecular conformation between the electrodes, and the electronic structure of the molecule/electrode interface. In this work, we perform an ab initio density-functional-theory investigation of the structural and transport properties through self-assembled CuPc molecules sandwiched between gold contacts with (111) surfaces. We demonstrated (i) a tunneling regime ruled by the pi orbitals of the aromatic rings of CuPc molecules; and (ii) a high variation (up to two orders of magnitude) of the current density with the orientation of the CuPc molecules relative to the gold surface. The source of this variation is the geometrical dependence of the energy of the highest-occupied-molecular-orbital with respect to the chemical potential of the metal and the generation of intra-molecular transport channels for a configuration with CuPc molecules tilted with respect to the gold surface. (AU)

• FAPESP's process: 17/02317-2 - Interfaces in materials: electronic, magnetic, structural and transport properties
• Grantee: Adalberto Fazzio
• Support Opportunities: Research Projects - Thematic Grants