Highly Dichroic Bisazomethine Dye Films on Friction-transferred Poly(tetrafluoroethylene) Layers

Abstract

Highly anisotropic thin molecular films have been successfully prepared by depositing a bisazomethine dye under vacuum through evaporation on friction-transferred (FT) poly(tetrafluoroethylene) (PTFE) layers. The layers induce the high orientational degrees showing high dichroic ratios over 20 in their polarized UV–visible absorption spectra. Moreover, by modifying FT layers with the further PTFE evaporated and rubbing, the ratios are improved to remarkable values up to 44.

Influence of the grain orientation on the charge transport properties of organic field-effect transistors

“…† These data are consistent with those obtained by the Hartree-Fock-based ZINDO/S approach. The demonstration of the main path for the charge carrier (15)(16)(17)(18)(19)(20)(21)(22) is conrmed. However, the ADF method shows that the LUMO splitting of the dimer (15-10) is also moderately large, suggesting that this path might be favorable to electron transport.…”

“…Molecular organization in the vapor-deposited J-aggregate organic thin lms of N,N 0 -bis[4-(N,N-diethylamino)benzylidene] diaminomaleonitrile (DE2), as well as their third-order nonlinear optical and photophysical properties was previously investigated in detail. [17][18][19][20][21][22] The chemical structure of this neutral dye 23 is shown in the inset of Fig. 1a.…”

“…Furthermore, the DE2 molecules can be highly oriented by depositing the dye on aligned poly(tetrauoroethylene) (PTFE) 26,27 layer, thereby forming lms with large degrees of in-plane anisotropy and dichroic ratios of up to 40. 21,22 Such a high degree of molecular orientation should have a signicant effect on charge transport properties.…”

The effect of terminal dimethyl and diethyl substituents on the J-aggregate-like molecular arrangement of bisazomethine dye molecules

“…Possible applications of these films include organic semiconductors and field-effect transistors. [23][24][25][26] However, these DE2 films also include non-aggregated solid phases, and these are responsible for the broad absorptions seen at shorter wavelengths. 27 In order to solve this problem, novel bisazomethine dyes have been synthesised [28][29][30][31] based on the reported crystal structures of DE2 and other bisazomethine dyes [32][33][34][35] and the proposed structural models of J-aggregates.…”

“…This can guide the molecular design of bisazomethine dyes. [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] Also, the relationship between substitution and the bulk structure can be extended to design organic compounds used in semiconductors. [36][37][38]…”