Saturation of Absorption and Fluorescence in Solutions of Phthalocyanines
| Autor: | Sol E. Harrison, Walter F. Kosonocky |
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| Rok vydání: | 1966 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 37:4789-4797 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.1708139 |
| Popis: | Lifetimes of the excited states of phthalocyanines are studied by the irradiation of solutions with a Q‐switched ruby laser. By detailed measurements of the saturation of fluorescence and absorption with increasing‐pulse laser power, the radiative and the nonradiative lifetimes of S1 as well as the time constants for the S1 → T1 and T1 → S0 transitions are determined. The transition between the ground state and the first excited singlet state in the metal‐free as well as the metallophthalocyanine saturates at laser pulse flux power densities of 0.1 to 0.15 MW/cm2. A complete transition of the molecular system from a ground state, S0, into a triplet state, T1, is observed in the case of the metal‐free phthalocyanine H2Pc. The triplet state has a relaxation time to the ground state of 1.0 μsec at 300°K and 150 μsec at 77°K. The absence of fluorescence in VOPc and CuPc implies that a third state also is involved in the saturation of the absorption of the metallophthalocyanines. In these solutions, the satura... |
| Databáze: | OpenAIRE |
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