Berlin 2024 – scientific programme

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O: Fachverband Oberflächenphysik

O 68: Poster: Scanning Probe Techniques: Method Development

O 68.5: Poster

Wednesday, March 20, 2024, 18:00–20:00, Poster C

Molecular behaviour during SPM tip functionalization for Scanning Quantum Dot Microscopy — •Paul Laubrock, Tim Dierker, and Philipp Rahe — Universität Osnabrück

Scanning quantum dot microscopy (SQDM) [1] is a variant of scanning probe microscopy (SPM) that enables the quantitative mapping of the electrostatic potential at the atomic scale [2]. A prerequisite for SQDM is the SPM tip functionalization with a (molecular) quantum dot. We developed an instructive flowchart for efficient preparation of functionalized SQDM tips based on scanning tunneling microscopy (STM) manipulation experiments at 5K with 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) molecules on Ag(111). Here we discuss experimental observations regarding the molecular behaviour in the tip-sample gap. In particular, we investigate an apparent instability in the STM signals appearing with a particular imaging contrast after lateral manipulation of a single PTCDA molecule. We interpret this and further observations in the context of dynamic bond formation/breaking in the surface-molecule-tip system.

[1] C. Wagner et al., PRL 115, 026101 (2015)

[2] C. Wagner et al., Nat. Mater. 18, 853 (2019)

Keywords: SQDM; PTCDA; STM; AFM; Manipulation