Electrochemiluminescence properties of nematic liquid crystal cells doped with rubrene

摘要

Light-emitting properties in liquid-crystal (LC) electrochemiluminescent (ECL) cells doped with an organic fluorescent dye (rubrene) were investigated. LC-ECL cells function based on the collision (recombination) of oppositely charged radical ions (anions and cations), which move by an external electric field applied across the cell. In this work, to obtain large values of luminance and current, a heating stir process was introduced in a preparation procedure of rubrene-doped LC. It was found that the heating stir process dramatically improves both of the luminance and current. It is considered that the drastic increase of the luminance and current density is caused by the increase of the actual dye concentration. Next, to obtain polarized emission based on the orientational nature of the nematic LC, emission properties of an LC-ECL cell with an interdigitated electrode were investigated. As a result, the polarized emission from orientating dyes was confirmed although its polarization ratio was not so high.