Bipolar single-molecule electroluminescence and electrofluorochromism
- URL: http://arxiv.org/abs/2210.11118v2
- Date: Wed, 19 Jul 2023 13:34:10 GMT
- Title: Bipolar single-molecule electroluminescence and electrofluorochromism
- Authors: Tzu-Chao Hung, Roberto Robles, Brian Kiraly, Julian H. Strik, Bram A.
Rutten, Alexander A. Khajetoorians, Nicolas Lorente and Daniel Wegner
- Abstract summary: We investigate cationic and anionic fluorescence of individual zinc phthalocyanine (ZnPc) molecules adsorbed on ultrathin NaCl films on Ag (111) by using STML.
They depend on the tip-sample bias polarity and appear at threshold voltages that are correlated with the onset energies of particular molecular orbitals.
- Score: 50.591267188664666
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: Understanding the fundamental mechanisms of optoelectronic excitation and
relaxation pathways on the single-molecule level has only recently been started
by combining scanning tunneling microscopy (STM) and spectroscopy (STS) with
STM-induced luminescence (STML). In this paper, we investigate cationic and
anionic fluorescence of individual zinc phthalocyanine (ZnPc) molecules
adsorbed on ultrathin NaCl films on Ag(111) by using STML. They depend on the
tip-sample bias polarity and appear at threshold voltages that are correlated
with the onset energies of particular molecular orbitals, as identified by STS.
We also find that the fluorescence is caused by a single electron tunneling
process. Comparing with results from density functional theory calculations, we
propose an alternative many-body picture to describe the charging and
electroluminescence mechanism. Our study provides aspects toward well-defined
voltage selectivity of bipolar electrofluorochromism, as well as fundamental
insights regarding the role of transiently charged states of emitter molecules
within OLED devices.
Related papers
- Determining the molecular Huang-Rhys factor via STM induced luminescence [11.925958787012464]
tunneling microscopy induced luminescence (STML) can be used to probe the optical and electronic properties of molecules.
We model the molecule as a two-level system with the vibrational degrees of freedom.
We find that the differential conductance, varying with the bias voltage, exhibits distinct step structure with various vibronic coupling strength.
arXiv Detail & Related papers (2023-11-08T09:17:50Z) - Optical Characterization of a Single Quantum Emitter Based on Vanadium
Phthalocyanine Molecules [0.0]
Vanadium-oxide phthalocyanine (VOPc) molecules stand out as promising candidates due to their large coherence times measured in ensemble.
We show that single VOPc molecules with stable optical properties at room temperature can be isolated.
arXiv Detail & Related papers (2022-09-20T16:37:18Z) - Interplay of Structural Chirality, Electron Spin and Topological Orbital
in Chiral Molecular Spin Valves [0.0]
Chirality has been a property of central importance in chemistry and biology for more than a century, and is now taking on increasing relevance in condensed matter physics.
electrons were found to become spin polarized after transmitting through chiral molecules, crystals, and their hybrids.
This phenomenon, called chirality-induced spin selectivity (CISS), presents broad application potentials and far-reaching fundamental implications.
arXiv Detail & Related papers (2022-09-16T18:05:29Z) - Real-time equation-of-motion CC cumulant and CC Green's function
simulations of photoemission spectra of water and water dimer [54.44073730234714]
We discuss results obtained with the real-time equation-of-motion CC cumulant approach.
We compare the ionization potentials obtained with these methods for the valence region.
We analyze unique features of the spectral functions, associated with the position of satellite peaks, obtained with the RT-EOM-CC and CCGF methods.
arXiv Detail & Related papers (2022-05-27T18:16:30Z) - Single quantum emitters with spin ground states based on Cl bound
excitons in ZnSe [55.41644538483948]
We show a new type of single photon emitter with potential electron spin qubit based on Cl impurities inSe.
Results suggest single Cl impurities are suitable as single photon source with potential photonic interface.
arXiv Detail & Related papers (2022-03-11T04:29:21Z) - Heralded spectroscopy reveals exciton-exciton correlations in single
colloidal quantum dots [0.8911822441893501]
We introduce biexciton heralded spectroscopy, enabled by a single-photon avalanche diode array based spectrometer.
This allows us to directly observe biexciton-exciton emission cascades and measure the biexciton binding energy of single quantum dots at room temperature.
We uncover correlations hitherto masked in ensembles, of the biexciton binding energy with both charge-carrier confinement and fluctuations of the local electrostatic potential.
arXiv Detail & Related papers (2021-08-01T00:41:57Z) - Chemical tuning of spin clock transitions in molecular monomers based on
nuclear spin-free Ni(II) [52.259804540075514]
We report the existence of a sizeable quantum tunnelling splitting between the two lowest electronic spin levels of mononuclear Ni complexes.
The level anti-crossing, or magnetic clock transition, associated with this gap has been directly monitored by heat capacity experiments.
The comparison of these results with those obtained for a Co derivative, for which tunnelling is forbidden by symmetry, shows that the clock transition leads to an effective suppression of intermolecular spin-spin interactions.
arXiv Detail & Related papers (2021-03-04T13:31:40Z) - Quantum Sensors for Microscopic Tunneling Systems [58.720142291102135]
tunneling Two-Level-Systems (TLS) are important for micro-fabricated quantum devices such as superconducting qubits.
We present a method to characterize individual TLS in virtually arbitrary materials deposited as thin-films.
Our approach opens avenues for quantum material spectroscopy to investigate the structure of tunneling defects.
arXiv Detail & Related papers (2020-11-29T09:57:50Z) - Exciton-trion dynamics of a single molecule in a radio-frequency cavity [0.0]
Trions and neutral excitons can be efficiently induced in single molecules by tip-enhanced spectromicroscopic techniques.
Here, we investigate exciton-trion dynamics by phase fluorometry, combining radio-frequency scanning tunnelling luminescence with time-resolved single photon detection.
We generate excitons and trions in single Zinc Phthalocyanine (ZnPc) molecules on NaCl/Ag(111), determine their dynamics and trace the evolution of the system in the picosecond range with atomic resolution.
arXiv Detail & Related papers (2020-11-28T09:17:34Z) - Effect of phonons on the electron spin resonance absorption spectrum [62.997667081978825]
We model the effect of phonons and temperature on the electron spin resonance (ESR) signal in magnetically active systems.
We find that the suppression of ESR signals is due to phonon broadening but not based on the common assumption of orbital quenching.
arXiv Detail & Related papers (2020-04-22T01:13:07Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.