Multi-layered carbon nanotube UV polariser for photo-alignment of liquid crystals

Abstract

An efficient ultraviolet (UV) polariser based on multi-layered carbon nanotubes (CNTs) which is obtained by set of CNT films attached to substrate in series with matching orientations is demonstrated. The degree of polarisation in the UV region increases with increasing number of CNT layers, reaching ~91% in the CNT polariser with 12 layers. A thin film with photoalignment polymer exposed with more than eight layers CNT polariser induces excellent homogenous liquid crystal (LC) alignment. The fringe-field switching (FFS) LC device with the photoalignment layer shows excellent electro-optics comparable to that with conventional metallic wire-grid polariser (WGP). The work proposes cost-effective novel polariser replacing WGP for photoalignment of LC.