Radiative defects and optical response in oriented para-hexaphenyl films
| Autor: | Ma Loi, Antonio Andrea Mura, Wilhelm Graupner, Günther Leising, A. Piaggi, F. Meghdadi, M Ariu, Giovanni Bongiovanni, L. Rossi |
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| Přispěvatelé: | Zernike Institute for Advanced Materials, Photophysics and OptoElectronics, University of Groningen |
| Rok vydání: | 1999 |
| Předmět: |
Photoluminescence
Materials science Absorption spectroscopy business.industry Analytical chemistry General Physics and Astronomy Substrate (electronics) Crystal Radiative transfer Optoelectronics Degree of polarization Irradiation Physical and Theoretical Chemistry Absorption (electromagnetic radiation) business |
| Zdroj: | Scopus-Elsevier Chemical Physics Letters, 313(3), 405-410. ELSEVIER SCIENCE BV |
| ISSN: | 0009-2614 |
| Popis: | The optical properties of an ordered para-hexaphenyl film, grown with molecules lying parallel to the substrate, are investigated. The absorption spectrum exhibits two peaks at 3.1 (L) and 4.35 (H) eV, featuring a different degree of polarization. The photoluminescence emission and the absorption at 3.1 eV are highly polarized. The presence of the L peak is strongly related to the growth conditions, and is favored at high deposition rates and low substrate temperatures. Upon 4.66 eV ultraviolet irradiation in air, the photoluminescence intensity and the absorption at 3.1 eV are reduced. Conversely, transitions at higher energies are almost unaffected by irradiation. Experimental data show that the L peak and emission arise from a crystal defect. |
| Databáze: | OpenAIRE |
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