Direct Emission of Continuously Varying Polarization of Light by Surface Treatment of a Mesogenic Luminophore

Abstract

Control of the polarized light generated from a luminophore has been intensively studied in organic light emitting diodes due to an enhancement of light intensity. The direct emission of highly circularly polarized light has been reported in a twist stacking of an achiral conjugated polymer by boundary surface effect without any chiral dopant. Although the twisted configuration of the emitting layer was obtained by applying different boundary conditions to two interfaces of the conjugated polymer, little study has been performed on the effect of the interfaces of the mesogenic polymer so far. Here, twist-angle-varying configuration in a single luminophore is designed and demonstrated to investigate an interfacial effect such as surface anchoring phenomena of conjugated mesogenic polymer. The continuously varying twisted configuration is fabricated by applying the circularly and unidirectionally rubbing method to the lower and the upper interfaces of the mesogenic luminophore, respectively. The surface anchoring and bulk elastic properties of luminophores are systematically analyzed to investigate twist deformation. Furthermore, a self-luminous light source generating continuously varying polarization of light is demonstrated. The proposed light source can generate multi-polarization states including linearly polarized, right-handed circularly polarized, and left-handed circularly polarized light in a single substrate.