Study of a liquid crystal structure with improved electro-optical characteristics

Abstract

This paper introduces the vertically aligned twisted nematic in-plane switching (VPS) structure, and compares the electro-optical (EO) characteristics of VPS liquid crystal displays (LCDs) and in-plane switching (IPS) LCDs. Various VPS-LCD pretilt angles were induced, and ion beam (IB) irradiation was used to enhance the EO properties. An x-ray photoelectron spectroscopic analysis of the IB-irradiated polymer surface confirmed that the intensity of C=O bonding as a function of exposure time traced the pretilt angles. The pretilt angle effect on optical properties was first analyzed in the experimental results. While multidomain vertical alignment LCDs and IPS-LCDs only resolve one difficulty, the VPS-LCDs described here overcome several viewing angle and transmittance curve problems.

Liquid Crystal Alignment Capabilities on SiNx Thin Films Via Ion-Beam Irradiation

“…In particular, vertical alignment (VA)-mode advanced LCDs with a wide viewing angle that been adopted by Sony and Samsung electronics. In this paper, we present the previously unreported vertical alignment characteristics of LCs on SiNx thin films, when the LC alignment is performed by IB irradiation on deposited SiNx as the plasma-enhanced chemical vapor deposition (PECVD) [12][13][14]. The pretilt angles generated on the SiNx were displayed under carefully controlled conditions such as an incident energy.…”

Surface oxidation and charge transfer inducing dipole–dipole interactions for homogeneous liquid crystal orientation

“…Organic and inorganic liquid crystal (LC) alignment layers have been widely studied by several groups [1][2][3][4][5][6][7][8][9]. Although inorganic LC alignment layers are in the spotlight these days [3][4][5][6][7], organic materials for LC alignment layers such as polyimide (PI) and polystyrene (PS) should be studied because it is easy to coat organic materials on glass substrates, which can save time in the fabrication of liquid crystal display (LCD) devices.…”

“…Although inorganic LC alignment layers are in the spotlight these days [3][4][5][6][7], organic materials for LC alignment layers such as polyimide (PI) and polystyrene (PS) should be studied because it is easy to coat organic materials on glass substrates, which can save time in the fabrication of liquid crystal display (LCD) devices. Recently, several groups studied ion beam (IB) bombardment as a LC alignment method which provides controllability, a nonstop process and a high resolution display [1,[4][5][6][7][8][9]. As a noncontact process, the IB method could solve several problems such as electrostatic discharge, debris and 4 Author to whom any correspondence should be addressed.…”

“…uneven roller traverse induced by a contact process of the conventional rubbing method. Our groups applied a Duo-PIGatron IB process having a dense and uniform Ar + plasma environment to induce LC alignment properties or improve organic thin-film transistor characteristics [4,5,[8][9][10][11]. The investigated IB process on PI alignment layers shows that the use of the IB device results in a similar stable LC alignment when compared with a conventional rubbing process [8,9].…”

“…Our groups applied a Duo-PIGatron IB process having a dense and uniform Ar + plasma environment to induce LC alignment properties or improve organic thin-film transistor characteristics [4,5,[8][9][10][11]. The investigated IB process on PI alignment layers shows that the use of the IB device results in a similar stable LC alignment when compared with a conventional rubbing process [8,9]. When using the IB device, selective breaking of C=O bonds and reformation of C-O bonds were observed by x-ray photoelectron spectroscopy (XPS) on IB-irradiated PI surfaces.…”