Non-Condon effect on charge transport in dithiophene-tetrathiafulvalene crystal

作者：Zhang, WeiWei; Liang, WanZhen^*; Zhao, Yi

来源：Journal of Chemical Physics, 2010, 133(2): 024501.

DOI：10.1063/1.3456545

• FIELD-EFFECT TRANSISTORS
• INTRAMOLECULAR ELECTRON-TRANSFER
• ORGANIC MOLECULAR-CRYSTALS
• AB-INITIO CALCULATIONS
• SINGLE-CRYSTALS
• REORGANIZATION ENERGY
• TRANSFER INTEGRALS
• SEMICONDUCTORS
• MOBILITY
• PARAMETERS

Combining first-principles calculations and non-Condon charge transfer rates proposed by us recently [Y. Zhao and W. Z. Liang, J. Chem. Phys. 130, 034111 (2009)], we investigated non-Condon effect on charge carrier mobility of organic semiconductor dithiophene-tetrathiafulvalene (DT-TTF) crystal. The first-principles results reveal that only several high-frequency intramolecular vibrational modes dominate the reorganization energy, and the nuclear-coordinate dependence of electronic coupling prefers to perform an exponential or Gaussian property for most intermolecular modes rather than a linear one as assumed in conventional models. Furthermore, the electronic coupling of an isolated DT-TTF dimer is indeed affected by the surrounding molecules. The predicted non-Condon mobilities with use of the obtained structure parameters are always greater than those from Condon approximation, and the non-Condon dynamic disorder is not important for DT-TTF, which is also confirmed by molecular dynamics simulation. More interestingly, the bandlike property can be predicted under the hopping mechanism when the nuclear tunneling is incorporated.

• 出版日期2010-7-14
• 单位厦门大学; 中国科学技术大学