Luminescence and absorption spectra of BEDT-TTF and its ion radical salt

✍ Scribed by M.E. Kozlov; Y. Tanaka; M. Tokumoto; T. Tani

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 496 KB
• Volume: 223
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(94)00464-1

✦ Synopsis

Photoluminescence spectra of the organic donor compound, bis(ethylenedithio)tetrathiafitlvalene (BEDT-TTF), has been observed in crystals and rigid solution at liquid He temperature. The spectra have similar shapes with a maximum at 1.96 eV and an intense sideband near 1.79 eV. A solid state effect reveals itself in low-temperature excitation spectra. A drastic increase in the excitation efftciency in the low-energy region (2.1-3.1 eV) compared to the high-energy one (3.1-4.0 eV) appears in the crystalline sample. The emission of BEDT-TTF is quenched by a modification of the degree of oxidation of molecules forming the crystal and is weak in the case of monovalent (BEDT-TTF)Br salt. The shapes of the luminescence spectra correlate with the absorption data of the substances. The recorded spectra are interpreted assuming a dimer-like arrangement of molecules in the investigated compounds.