Electric Field Oriented Nanostructured Organic Thin Films with Polarized Luminescence

Abstract

The effect of the external electric field of 105 V/m on the ordering of two luminescent liquid crystalline molecules (1-pentyl-2/,3/-difluoro-3///-methyl-4////-octyl-p-quinguephenyl and 9,10-Bis (4-pentylphenylethynyl)antracene) during thermal vacuum deposition is studied. The morphology, electrical conductivity, optical absorption, luminescence spectra, and polarization are presented and analyzed. All data show the formation of ordered films. The polarization degree is 60% for 1-pentyl-2/,3/-difluoro-3///-methyl-4////-octyl-p-quinguephenyl oriented films and 28% for 9,10-Bis (4-pentylphenylethynyl)antracene. The lower value of M2 luminescence polarization can be explained by the absence of dipole moment in this molecule.

Vapor-Deposited Glasses with Long-Range Columnar Liquid Crystalline Order

“…6 Films prepared in the presence of external fields can also exhibit anisotropic packing and improved performance. 7,8 Liquid crystalline systems have been exploited for organic electronic applications as a result of their propensity to selfassemble into highly ordered, anisotropic structures. 9−11 Columnar liquid crystalline systems, in particular, are ideal candidates for organic semiconducting devices as they self-assemble into columnar superstructures governed, in part, by molecular cores rich in π-electrons.…”

“…Lattice strain, in combination with solution-shearing, has been used to further increase orbital overlap between component molecules, thereby further enhancing mobility . Films prepared in the presence of external fields can also exhibit anisotropic packing and improved performance. , …”