共 48 条
Dynamics of the intermolecular transfer integral in crystalline organic semiconductors
被引:346
作者:
Troisi, A
[1
]
Orlandi, G
机构:
[1] Univ Warwick, Dept Chem, Coventry CV4 7AL, W Midlands, England
[2] Univ Bologna, Dipartimento Chim G Ciamician, I-40126 Bologna, Italy
关键词:
D O I:
10.1021/jp055432g
中图分类号:
O64 [物理化学(理论化学)、化学物理学];
学科分类号:
070304 ;
081704 ;
摘要:
In organic crystalline semiconductor molecular components are held together by very weak interactions and the transfer integrals between neighboring molecular orbitals are extremely sensitive to small nuclear displacements. We used a mixed quantum chemical and molecular dynamic methodology to assess the effect of nuclear dynamics on the modulation of the transfer integrals between close molecules. We have found that the fluctuations of the transfer integrals are of the same order of magnitude of their average value for pentacene and anthracene. Under these conditions the usual perturbative treatment of the electron-phonon coupling is invalid, the band description of the crystal breaks down and the charge carriers become localized. Organic crystals of pentacene and anthracene, even in the absence of defects, can be regarded as disordered media with respect to their charge transport properties. These results suggest that the dynamic electronic disorder can be the factor limiting the charge mobility in crystalline organic semiconductors.
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页码:4065 / 4070
页数:6
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