Charged optical excitations (trions) generated by charge carrier injection are crucial for emerging optoelectronic technologies as they can be produced and manipulated by electric fields. Trions and neutral excitons can be efficiently induced in single molecules by means of tip-enhanced spectromicroscopic techniques. However, little is known of the exciton-trion dynamics at single molecule level as this requires methods permitting simultaneous subnanometer and subnanosecond characterization. Here, we investigate exciton-trion dynamics by phase fluorometry, combining radio frequency modulated scanning tunnelling luminescence with time-resolved single photon detection. We generate excitons and trions in single Zinc Phthalocyanine (ZnPc) molecules on NaCl/Ag(111), and trace the evolution of the system in the picosecond range. We explore the dependence of effective lifetimes on bias voltage and describe the conversion mechanism from neutral excitons to trions, via charge capture, as the primary pathway to trion formation. We corroborate the dynamics of the system by a causally deterministic four-state model.

Faculty of Mathematics and Physics Charles University Ke Karlovu 3 CZ12116 Praha 2 Czech Republic

Institute of Physics Czech Academy of Sciences Cukrovarnická 10 112 CZ16200 Praha 6 Czech Republic

Instituto de Ciencia de Materiales de Madrid CSIC Sor Juana Inés de la Cruz 3 E28049 Madrid Spain

Instituto de Física Fundamental CSIC Serrano 121 E28006 Madrid Spain

Regional Centre of Advanced Technologies and Materials Šlechtitelů 27 CZ78371 Olomouc Czech Republic

Zobrazit více v PubMed

Apkarian VA, Schwentner N. Molecular Photodynamics in Rare Gas Solids. Chem Rev. 1999;99:1481–1514. PubMed

Lounis B, Moerner WE. Single Photons on Demand From a Single Molecule at Room Temperature. Nature. 2000;407:491–493. PubMed

Beveratos A, Brouri R, Gacoin T, Villing A, Poizat J-P, Grangier P. Single Photon Quantum Cryptography. Phys Rev Lett. 2002;89:187901. PubMed

O’Brien JL. Optical Quantum Computing. Science. 2007;318:1567–1570. PubMed

Kuhnke K, Große C, Merino P, Kern K. Atomic-Scale Imaging and Spectroscopy of Electroluminescence at Molecular Interfaces. Chem Rev. 2017;117:5174–5222. PubMed

Rosławska A, Leon CC, Grewal A, Merino P, Kuhnke K, Kern K. Atomic-Scale Dynamics Probed by Photon Correlations. ACS Nano. 2020;14:6366–6375. PubMed PMC

Chen C, Chu P, Bobisch CA, Mills DL, Ho W. Viewing the Interior of a Single Molecule: Vibronically Resolved Photon Imaging at Submolecular Resolution. Phys Rev Lett. 2010;105:217402. PubMed

Zhang Y, Luo Y, Zhang Y, Yu Y, Kuang Y, Zhang L, Meng Q, Luo Y, Yang J, Dong Z, Hou JG. Visualizing Coherent Intermolecular Dipole–Dipole Coupling in Real Space. Nature. 2016;531:623–627. PubMed

Kimura K, Miwa K, Imada H, Imai-Imada M, Kawahara S, Takeya J, Kawai M, Galperin M, Kim Y. Selective Triplet Exciton Formation in a Single Molecule. Nature. 2019;570:210–213. PubMed

Chen G, Luo Y, Gao H, Jiang J, Yu Y, Zhang L, Zhang Y, Li X, Zhang Z, Dong Z. Spin-Triplet-Mediated Up-Conversion and Crossover Behavior in Single-Molecule Electroluminescence. Phys Rev Lett. 2019;122:177401. PubMed

Doležal J, Mutombo P, Nachtigallová D, Jelínek P, Merino P, Švec M. Mechano-Optical Switching of a Single Molecule With Doublet Emission. ACS Nano. 2020;14:8931–8938. PubMed PMC

Doppagne B, Chong MC, Bulou H, Boeglin A, Scheurer F, Schull G. Electrofluorochromism at the Single-Molecule Level. Science. 2018;361:251–255. PubMed

Farrukh A, Tian X, Kong F, Yu Y, Jing S, Chen G, Zhang Y, Liao Y, Zhang Y, Dong Z. Bias-Polarity Dependent Electroluminescence From a Single Platinum Phthalocyanine Molecule. Chin J Chem Phys. 2020;34:87–94.

Merino P, Große C, Rosławska A, Kuhnke K, Kern K. Exciton Dynamics of C60-Based Single-Photon Emitters Explored by Hanbury Brown–Twiss Scanning Tunnelling Microscopy. Nat Commun. 2015;6:8461. PubMed PMC

Merino P, Rosławska A, Leon CC, Grewal A, González C, Kuhnke K, Kern K. A Single Hydrogen Molecule as an Intensity Chopper in an Electrically Driven Plasmonic Nanocavity. Nano Lett. 2019;19:235–241. PubMed PMC

Zhang L, Yu Y, Chen L, Luo Y, Yang B, Kong F, Chen G, Zhang Y, Zhang Q, Luo Y, Yang J, et al. Electrically Driven Single-Photon Emission From an Isolated Single Molecule. Nat Commun. 2017;8:580. PubMed PMC

Leon CC, Rosławska A, Grewal A, Gunnarsson O, Kuhnke K, Kern K. Photon Superbunching From a Generic Tunnel Junction. Sci Adv. 2019;5:eaav4986. PubMed PMC

Leon CC, Gunnarsson O, de Oteyza DG, Rosławska A, Merino P, Grewal A, Kuhnke K, Kern K. Single Photon Emission From a Plasmonic Light Source Driven by a Local Field-Induced Coulomb Blockade. ACS Nano. 2019;14:4216–4223. PubMed PMC

Doppagne B, Neuman T, Soria-Martinez R, López LEP, Bulou H, Romeo M, Berciaud S, Scheurer F, Aizpurua J, Schull G. Single-Molecule Tautomerization Tracking Through Space–And Time-Resolved Fluorescence Spectroscopy. Nat Nanotechnol. 2020;15:207–211. PubMed

Rosławska A, Merino P, Große C, Leon CC, Gunnarsson O, Etzkorn M, Kuhnke K, Kern K. Single Charge and Exciton Dynamics Probed by Molecular-Scale-Induced Electroluminescence. Nano Lett. 2018;18:4001–4007. PubMed

Lee J, Perdue SM, Perez AR, Apkarian VA. Vibronic Motion With Joint Angstrom–Femtosecond Resolution Observed Through Fano Progressions Recorded Within One Molecule. ACS Nano. 2014;8:54–63. PubMed

Grosse C, Etzkorn M, Kuhnke K, Loth S, Kern K. Quantitative Mapping of Fast Voltage Pulses in Tunnel Junctions by Plasmonic Luminescence. Appl Phys Lett. 2013;103:183108

Martín-Jiménez A, Fernández-Domínguez AI, Lauwaet K, Granados D, Miranda R, García-Vidal FJ, Otero R. Unveiling the Radiative Local Density of Optical States of a Plasmonic Nanocavity by STM. Nat Commun. 2020;11:1021. PubMed PMC

Luo Y, Chen G, Zhang Y, Zhang L, Yu Y, Kong F, Tian X, Zhang Y, Shan C, Luo Y, Yang J, et al. Electrically Driven Single-Photon Superradiance From Molecular Chains in a Plasmonic Nanocavity. Phys Rev Lett. 2019;122:233901. PubMed

Doležal J, Merino P, Redondo J, Ondič L, Cahlík A, Švec M. Charge Carrier Injection Electroluminescence With CO-Functionalized Tips on Single Molecular Emitters. Nano Lett. 2019;19:8605–8611. PubMed PMC

Neuman T, Esteban R, Casanova D, García-Vidal FJ, Aizpurua J. Coupling of Molecular Emitters and Plasmonic Cavities Beyond the Point-Dipole Approximation. Nano Lett. 2018;18:2358–2364. PubMed

Zhang Y, Meng Q, Zhang L, Luo Y, Yu Y, Yang B, Zhang Y, Esteban R, Aizpurua R, Luo Y, Yang J, et al. Sub-Nanometre Control of the Coherent Interaction Between a Single Molecule and a Plasmonic Nanocavity. Nat Commun. 2017;8:15225. PubMed PMC

Yang B, Chen G, Ghafoor A, Zhang Y, Zhang Y, Zhang Y, Luo Y, Yang J, Sandoghdar V, Aizpurua J, Dong Z, et al. Sub-Nanometre Resolution in Single-Molecule Photoluminescence Imaging. Nat Photon. 2020;14:693–699.

Zhang XF, Xu HJ. Influence of Halogenation and Aggregation on Photosensitizing Properties of Zinc Phthalocyanine (ZnPC) J Chem Soc, Faraday Trans. 1993;89:3347–3351.

Harats MG, Kirchhof JN, Qiao M, Greben K, Bolotin KI. Dynamics and Efficient Conversion of Excitons to Trions in Non-Uniformly Strained Monolayer WS2. Nat Photon. 2020;14:324–329.

Frisch MJ, Trucks GW, Schlegel HB, Scuseria GE, Robb MA, Cheeseman JR, Scalmani G, Barone V, Petersson GA, Nakatsuji H, Li X, et al. Gaussian 16, Revision A.03. Gaussian, Inc; Wallingford CT: 2016.

Chai J-D, Head-Gordon M. Long-Range Corrected Hybrid Density Functionals with Damped Atom-Atom Dispersion Corrections. Phys Chem Chem Phys. 2008;10:6615–6620. PubMed

Lu T, Chen F. Multiwfn: A Multifunctional Wavefunction Analyzer. J Comput Chem. 2012;33:580–592. PubMed

Resonant Tip-Enhanced Raman Spectroscopy of a Single-Molecule Kondo System

Single-Molecule Time-Resolved Spectroscopy in a Tunable STM Nanocavity

Evidence of exciton-libron coupling in chirally adsorbed single molecules