Resumen
The optical absorption of n-type (C60 and PTCDA) and p-type (CuPc and pentacene) organic semiconductors is investigated by optical transmission and photothermal deflection spectroscopy. The usual absorption bands related to HOMO-LUMO transitions are observed in the high absorption region of transmission spectra. Photothermal deflection spectroscopy also evidences exponential absorption shoulders with characteristic energies 47 meV for CuPc, 38 meV for pentacene, 50 meV for PTCDA and 87 meV for C60. In addition, broad bands in the low absorption level are observed for C60 and PTCDA. These bands have been attributed to contamination due to air exposure. On the other hand, in CuPc a clear absorption peak at 1.12 eV is observed with smaller features at 1.04 eV, 1.20 eV and 1.33 eV. These peaks are attributed to transitions between the Pc levels of CuPc ions. Finally, the optical absorption expected in blends of organic semiconductors is estimated by an effective media approximation.
Idioma original | Inglés |
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Páginas (desde-hasta) | 1663-1667 |
Número de páginas | 5 |
Publicación | Journal of Non-Crystalline Solids |
Volumen | 352 |
N.º | 9-20 SPEC. ISS. |
DOI | |
Estado | Publicada - 15 jun. 2006 |
Publicado de forma externa | Sí |