Optical and electrical anisotropy of ordered layers of rigid core semiconductor – dithienothiophene derivative

Abstract

Abstract. Preparation of highly oriented layers of organic semiconductor -dithienothiophene derivative is described. The layers were obtained by zone-casting technique -a solution based one step method that does not require the use of preoriented substrates. Unidirectional alignment of the dithienothiophene derivative molecules in the zone-cast layers was confirmed by absorption and photoluminescence polarized spectra. Anisotropy of electrical properties was characterised by means of anisotropy of charge carrier mobility in field effect transistors (FETs). The FET devices were fabricated in bottom contacts -bottom gate configuration with the channel lengths parallel and perpendicular to the crystal growth direction, respectively. The FET mobility determined in the direction parallel to the zone-casting direction is ca. 1 order of magnitude higher than those in the perpendicular direction.

Role of geometry, substrate and atmosphere on performance of OFETs based on TTF derivatives

“…layer [9], but one should remember, that for this family of TTF derivatives it is very difficult to get crystals perfect enough to determine their crystals structure. So far only for TTF-4SC n with n<9 it was possible to determine the single crystals structure [23].…”

“…Because of the strong correlation between the crystal structure and the device performance methods of controlled layer deposition are needed. One of such methods is the zone-casting technique [6], which allows to produce highly ordered layers of "p" and "n" type low molecular weight semiconductors [7,8,9] and discotic liquid crystals [10,11].…”

Structural, Thermo-Optical, and Photophysical Properties of Highly Oriented Thin Films of Quinoxalinophenanthrophenazine Derivative

“…The zone-casting technique was first reported in 1981 , and has been widely used to align materials (even if they do not exhibit self-assembly behavior) over a large area. Indeed, many materials were efficiently processed for organic field-effect transistors ,,− and organic photovoltaic devices …”