Enhancing intramolecular features and identifying defects in organic and hybrid nanoarchitectures on a metal surface at room temperature using a NaCl-functionalized scanning tunneling microscopy tip

Abstract

International audienceScanning tunneling microscopy (STM) is a powerful method to characterize two-dimensional organic structures and their local electronic properties. Intermolecular features are usually routinely revealed using STM at very low temperature. The resolution of STM images recorded at room temperature is in comparison quite limited. We investigate here the morphology and local electronic properties of organic and hybrid nanoarchitectures laying on metal surface at room temperature using STM with a classical PtIr tip and a novel NaCl-functionalised tip. STM images show that the NaCl-functionalized tip allows revealing at room temperature intermolecular features and variation of molecular local electronic properties, that are not visible using a PtIr tip. This new method opens new opportunities for characterizing and assessing at the atomic scale the morphology and electronic properties of organic nanoarchitectures on highly conductive surfaces not only at room temperature but also at low temperature

Elucidating the intramolecular contrast in the STM images of 2,4,6-tris(4′,4′′,4′′′-trimethylphenyl)-1,3,5-triazine molecules recorded at room-temperature and at the liquid-solid interface

“…[44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62] NaCl functionalised STM tip has been used to enhanced intramolecular features in organic and hybrid nanoarchitectures on a metal surface at room temperature in vacuum. 63 It was thus possible to reveal that the intramolecular features correspond to the lowest unoccupied molecular orbitals (LUMO). SPM tips can hardly be functionalized at the solid-liquid interface at room temperature, but intramolecular features in organic layers have been sometimes reported.…”