Single charge and exciton dynamics probed by molecular-scale-induced electroluminescence

Abstract

Excitons and their constituent charge carriers play the central role in electroluminescence mechanisms determining the ultimate performance of organic optoelectronic devices. The involved processes and their dynamics are often studied with time-resolved techniques limited by spatial averaging that obscures the properties of individual electron-hole pairs. Here we overcome this limit and characterize single charge and exciton dynamics at the nanoscale by using time-resolved scanning tunnelling microscopy-induced luminescence (TR-STML) stimulated with nanosecond voltage pulses. We use isolated defects in C${}_{60}$ thin films as a model system into which we inject single charges and investigate the formation dynamics of a single exciton. Tuneable hole and electron injection rates are obtained from a kinetic model that reproduces the measured electroluminescent transients. These findings demonstrate that TR-STML can track dynamics at the quantum limit of single charge injection and can be extended to other systems and materials important for nanophotonic devices.

References in corpus (8)

• Fluorescence and phosphorescence from individual C${}_{60}$ molecules excited by local electron tunneling
• Orbital-selective single molecule excitation and spectroscopy based on plasmon-exciton coupling
• Electrically-driven vibronic spectroscopy with sub-molecular resolution
• Time-Resolved Single Dopant Charge Dynamics in Silicon
• Time-Resolved Imaging of Negative Differential Resistance on the Atomic Scale
• Resonant heating and substrate-mediated cooling of a single C60 molecule in a tunnel junction
• Versatile scanning tunneling microscopy with 120ps time resolution
• Resolving and Tuning Carrier Capture Rates at a Single Silicon Atom Gap State

Cited by in corpus (10)

• Electrically driven photon emission from individual atomic defects in monolayer WS2
• Charge carrier injection electroluminescence with CO functionalized tips on single molecular emitters
• Exciton-trion dynamics of a single molecule in a radio-frequency cavity
• Atomic-scale structural fluctuations of a plasmonic cavity
• Single Photon Emission from a Plasmonic Light Source Driven by a Local Field-Induced Coulomb Blockade
• A single hydrogen molecule as an intensity chopper in an electrically-driven plasmonic nanocavity
• Gigahertz frame rate imaging of charge-injection dynamics in a molecular light source
• Directly profiling the dark-state transition density via scanning tunneling microscope
• Measuring fine molecular structures with luminescence signal from an alternating current scanning tunneling microscope
• Orbitally resolved single-photon emission from an individual atomic vacancy center in a semiconductor