Abstract
We have used scanning tunnelling microscopy (STM) at 77 K to investigate3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) moleculesadsorbed on an ultrathin (1–2 monolayer (ML)) film of KBr grown on ac(8 × 2)InSb(001) substrate. The molecules are stabilized both at the KBr steps and on the terraces. On the1 ML film the PTCDA molecules appear predominantly as single entities, whereas on the2 ML film formation of molecular clusters is preferred. Differences in the adsorptionconfigurations indicate that the interaction between the molecules and the surface differssignificantly for the cases of 1 and 2 ML films. We present images of the molecules obtainedwith sub-molecular resolution for both filled and empty state sampling modes. We arguethat the highest occupied molecular orbital (the lowest unoccupied molecular orbital) isresponsible for intramolecular contrast in filled (empty) state images of the molecules,even though they are deformed due to strong interaction with the substrate.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
