Ionization energy and energy gap structure of MoSI molecular wires: Kelvin probe, ultraviolet photoelectron spectroscopy, and cyclic voltammetry measurements

Martin Strojnik; Ales Omerzu; Aleksej Majkić; Peter M Mihailovic; Junos Lukan; Gregor Bavdek; Gvido Bratina; Dean Cvetko; Peter Topolovsek; Dragan Mihailovic

doi:10.1021/la1050767

Ionization energy and energy gap structure of MoSI molecular wires: Kelvin probe, ultraviolet photoelectron spectroscopy, and cyclic voltammetry measurements

Langmuir. 2011 Apr 19;27(8):4296-9. doi: 10.1021/la1050767. Epub 2011 Mar 17.

Authors

Martin Strojnik¹, Ales Omerzu, Aleksej Majkić, Peter M Mihailovic, Junos Lukan, Gregor Bavdek, Gvido Bratina, Dean Cvetko, Peter Topolovsek, Dragan Mihailovic

Affiliation

¹ Jozef Stefan Institute, Ljubljana, Slovenia. martin.strojnik@ijs.si

PMID: 21413723
DOI: 10.1021/la1050767

Abstract

The work function W of Mo(6)S(3)I(6) molecular nanowires is determined by Kelvin probe (KP) measurements, UV photoelectron spectroscopy (UPS), and cyclic voltammetry (CV). The values obtained by all three methods agree well, giving W = 4.8 ± 0.1 eV. CV measurements also give a gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of E(g) = 1.2 ± 0.1 eV, in agreement with recent optical measurements, but in disagreement with theoretical calculations, which predict the material to be a metal. The electronic structure of Mo(6)S(3)I(6) suggests use of the material in applications such as bulk heterostructure photovoltaics and transparent electrodes and for molecular electronics devices.