Dresden 2020 – scientific programme

The DPG Spring Meeting in Dresden had to be cancelled! Read more ...

Parts | Days | Selection | Search | Updates | Downloads | Help

O: Fachverband Oberflächenphysik

O 15: Organic Molecules on Inorganic Substrates II: Mainly Porphyrins

O 15.9: Talk

Monday, March 16, 2020, 17:15–17:30, REC C 213

Real-space engineering the optoelectronic properties of single molecules — •Tzu-Chao Hung, Brian Kiraly, Julian Strik, Alexander Khajetoorians, and Daniel Wegner — Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands

While optical properties of light-emitting molecules are mostly studied via luminescence spectroscopy, several recent studies revealed a fundamental lack of understanding luminescence on the single-molecule level. Intermolecular and environmental interactions can have a significant impact on the optoelectronic properties but are hardly controllable in ensemble measurement. We combine STM/STS and atomic manipulation to study the STM-induced light emission of single molecules and molecular assemblies. Using zinc-phthalocyanine (ZnPc) molecules on ultrathin NaCl films, we demonstrate how the emission yield, energy shift and resolution of luminescence spectra change by anchoring ZnPc to a step edge or by assembling molecules into chains. This not only allows us to understand and disentangle the impact of intermolecular and molecule-substrate coupling on exciton lifetimes, but ultimately permits high-resolution vibronic spectroscopy providing a chemical fingerprint of single molecules. Furthermore, utilizing the tautomerism of H2Pc, which can be manipulated by the tunneling current, we study how to fine-tune dipole-dipole coupling, toward sub-molecular design of the spectroscopic response.