Closed-loop conductance scanning tunneling spectroscopy: demonstrating the equivalence to the open-loop alternative

• Main Authors: Chris Hellenthal, Kai Sotthewes, Martin H. Siekman, E. Stefan Kooij, Harold J. W. Zandvliet
• Format: Article
• Language: English
• Published: Beilstein-Institut 2015-05-01
• Series: Beilstein Journal of Nanotechnology
• Subjects: image charge; scanning tunneling spectroscopy (STS); tunneling barrier; work function; z(V)
• Online Access: https://doi.org/10.3762/bjnano.6.113
• ISSN: 2190-4286

We demonstrate the validity of using closed-loop z(V) conductance scanning tunneling spectroscopy (STS) measurements for the determination of the effective tunneling barrier by comparing them to more conventional open-loop I(z) measurements. Through the development of a numerical model, the individual contributions to the effective tunneling barrier present in these experiments, such as the work function and the presence of an image charge, are determined quantitatively. This opens up the possibility of determining tunneling barriers of both vacuum and molecular systems in an alternative and more detailed manner.