Room temperature excitonic coupling in self-assembled copper – Fullerene hybrid films exposed to ambient air

• Published in: Carbon (New York) Vol. 226; p. 119230
• Main Authors: Lavrentiev, Vasily, Chvostova, Dagmar, Klementova, Mariana, Kuldova, Karla, de Prado, Esther, Vacik, Jiri, Lavrentieva, Inna, Dejneka, Alexandr
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2024
• Subjects: Copper oxide; Exciton; Fullerene; Hybrid nanostructure; Resonant strong coupling; Fullerene; Resonant strong coupling; Hybrid nanostructure; Exciton; Copper oxide
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2024.119230

Analytically sound combination of organic and inorganic semiconductors in designing functional hybrid nanomaterials promises new advances in nanoscience and in creation of next-generation optoelectronic devices. In this work, we report on combining two contrasting semiconductors (inorganic and organic) possessing attractive optical and electronic properties, namely Cu2O (in form of small single-crystalline nanoparticles, NPs) and C60-fullerene (as a medium supporting the NP ensemble), which were formed within the well-controlled Cux(Oy)C60 hybrid films through self-assembling and ambient air exposure of the vapour-deposited Cu and C60 mixture. The controllability of the hybrid film nanostructure was established and verified through systematic study of the films using Rutherford backscattering spectrometry, transmission electron microscopy, X-ray diffraction, Raman spectrometry and spectroscopic ellipsometry. The remarkable coincidence of the optical absorption peaks around 3.5 eV, reported for the Wannier-Mott (WM) excitons in a Cu2O crystal and detected for the Frenkel (F) excitons in the pristine C60 film, allowed us to observe room temperature polaritons as a product of the F-WM excitonic strong coupling. Quite high coupling energy of the FWM hybrid exciton estimated for the Cux(Oy)C60 films in the x interval of 5 < x < 15 (from 390 meV to 610 meV) implies the mediated effect of nanocavity photons and quantum confinement effect, strongly enhancing the hybrid exciton coupling energy. The implemented study discloses the self-assembled Cux(Oy)C60 hybrid films as promising material for application in optoelectronics and nonlinear optics. [Display omitted]