In this paper, we show that simultaneous noncontact atomic force microscopy (nc-AFM) and scanning tunneling microscopy (STM) is a powerful tool for molecular discrimination on the Si(111)–7 × 7 surface, even at room temperature. We employ force spectroscopy to demonstrate that the force response allows us to distinguish between molecular adsorbates and common defects, such as vacancies, in good agreement with DFT calculations. Finally, we prove that STM/nc-AFM method is able to determine attachment sites of molecules deposited on semiconductor surface at room temperature. In conclusion, simultaneous nc-AFM/STM technique using a qPlus sensor enables new possibilities to characterize molecules on semiconductor surfaces.
Z. Majzik(1), B. Drevniok(2), W. Kamiński(3), M. Ondráček(1), A.B. McLean(2) and P. Jelínek(1)
(1)Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Prague, Czech Republic
(2)Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, Ontario, Canada K7L 3N6
(3)Institute of Experimental Physics, University of Wrocław, plac Maksa Borna 9, 50-204 Wrocław, Poland