Regensburg 2016 – scientific programme

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

HL: Fachverband Halbleiterphysik

HL 74: Transport: Molecular Electronics and Photonics 1 (Joint session of CPP, DS, HL, MA, O and TT, organized by TT)

HL 74.2: Talk

Thursday, March 10, 2016, 09:45–10:00, H23

STM-induced luminescence of single molecule junction — •Michael Chong¹, Gael Reecht¹, Hervé Bulou¹, Alex Boeglin¹, Fabrice Mathevet², Fabrice Scheurer¹, and Guillaume Schull¹ — ¹Institut de Physique et Chimie des Matériaux de Strasbourg - CNRS - France — ²Laboratoire de Chimie des Polymères - CNRS - Université Pierre et Marie Curie, Paris, France

Electroluminescence of a single molecule can be induced by means of scanning tunneling microscopy. When a molecule is placed between two metallic electrodes it is necessary to decouple it using thin insulating layers in order to measure its intrinsic luminescence. A direct contact with the electrodes (tip and substrate), necessary if we envision to build single molecule electronic devices, results in quenching or broadening of the fluorescence of the molecule. We use on-surface polymerization to embed a cromphore molecule in a molecular chain. The STM tip is then used to lift the chain in order to decouple the cromophore from the surface yet mantaining a circuit like configuration trough the molecular chain. The current generated by applying a bias to the electrodes excites the cromophore that then exhibits narrow line luminescence and vibronic peaks allowing chemical identification the emitting unit.

Moreover we demonstrate that this configuration allows to control the lifetime of the excited state of the emitting molecule by two orders of magnitude by changing the coupling of the single molecle with the substrate adjusting the tip-sample separation. This system might open the way to electro-plasmonic devices at the single molecule level.