The crystal structure and phonon dynamics of pentacene is computed with the Quasi Harmonic Lattice Dynamics (QHLD) method, based on atom-atom potential. We show that two crystalline phases of pentacene exist, rather similar in thermodynamic stability and in molecular density. The two phases can be easily distinguished by Raman spectroscopy in the 10 - 100 cm(-1) spectral region. We have not found any temperature induced phase transition, whereas a sluggish phase change to the denser phase is induced by pressure. The bandwidths of the two phases are slightly different. The charge carrier coupling to low-frequency phonons is calculated.
R.G. Della Valle, A. Brillante, L. Farina, E. Venuti, M. Masino, A. Girlando (2004). Organic semiconductors: Polymorphism, phonon dynamics and carrier-phonon coupling in pentacene. MOLECULAR CRYSTALS AND LIQUID CRYSTALS, 416, 145-154 [10.1080/15421400490478542].
Organic semiconductors: Polymorphism, phonon dynamics and carrier-phonon coupling in pentacene
DELLA VALLE, RAFFAELE GUIDO;BRILLANTE, ALDO;VENUTI, ELISABETTA;FARINA, LUCA
2004
Abstract
The crystal structure and phonon dynamics of pentacene is computed with the Quasi Harmonic Lattice Dynamics (QHLD) method, based on atom-atom potential. We show that two crystalline phases of pentacene exist, rather similar in thermodynamic stability and in molecular density. The two phases can be easily distinguished by Raman spectroscopy in the 10 - 100 cm(-1) spectral region. We have not found any temperature induced phase transition, whereas a sluggish phase change to the denser phase is induced by pressure. The bandwidths of the two phases are slightly different. The charge carrier coupling to low-frequency phonons is calculated.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
