scholarly journals Evaporative deposition of SiO2 nanoparticles multilayer on ITO substrates and application for vertical alignment of liquid crystals - Effect of dichroic dye

2021 ◽  
Vol 2070 (1) ◽  
pp. 012071
Author(s):  
Ankit Rai Dogra ◽  
Vandna Sharma ◽  
Partha Khanra ◽  
Pankaj Kumar
Keyword(s):  
Liquid Crystal ◽  
Indium Tin Oxide ◽  
Contrast Ratio ◽  
Sio2 Nanoparticles ◽  
Operating Voltage ◽  
Vertical Alignment ◽  
Dichroic Dye ◽  
Electro Optic ◽  
Coated Cell ◽  
Vertically Aligned

Abstract In this work the SiO2 nanoparticles layer was deposited by solvent evaporation on ITO substrates and used for vertical alignment of pure and dye doped liquid crystal (LC) in confined cells. The pure nematic liquid crystal (NLC) material was filled into SiO2 layer coated cell by the capillary injection method. The 0.5 wt.% of dichroic dye added into the LC mixture and studied its effect on electro-optic behaviour of display cell. The FESEM study reveals the multilayered deposition of the SiO2 on Indium tin oxide (ITO) substrates. Conoscopic and polarised optical microscopy (POM) study show good dark black and bright textures at OFF and ON state under the cross polarizers and confirm vertical alignment (VA) of LC molecules. The electro-optical (E-O) study shows the lower threshold and operating voltage with higher contrast ratio in dye doped vertically aligned LC (VALC) cell as compare to the pure SiO2 coated VALC cell.

scholarly journals Light Leakage of Multidomain Vertical Alignment LCDs Using a Colorimetric Model in the Dark State

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Chuen-Lin Tien ◽  
Rong-Ji Lin ◽  
Shang-Min Yeh
Keyword(s):  
Liquid Crystal ◽  
Contrast Ratio ◽  
Liquid Crystal Displays ◽  
Vertical Alignment ◽  
Dark State ◽  
Proposed Model ◽  
Color Shift ◽  
Depolarization Of Light ◽  
The Difference ◽  
Color Filters

Light leakage from liquid crystal displays in the dark state is relatively larger and leads to a degraded contrast ratio and color shift. This work describes a novel colorimetric model based on the Muller matrix that includes depolarization of light propagating through liquid crystal molecules, polarizers, and color filters. In this proposed model, the chromaticity can be estimated in the bump and no-bump regions of an LCD. We indicate that the difference between simulation and measurement of chromaticity is about 0.01. Light leakage in the bump region is three times that in no-bump region in the dark state.

scholarly journals Electrically Tunable-Focusing Liquid Crystal Microlens Array with Simple Electrode

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 431 ◽  
Author(s):  
Li-Lan Tian ◽  
Fan Chu ◽  
Hu Dou ◽  
Lei Li ◽  
Qiong-Hua Wang
Keyword(s):  
Liquid Crystal ◽  
Indium Tin Oxide ◽  
Focal Length ◽  
Microlens Array ◽  
Operating Voltage ◽  
Focusing Effect ◽  
Horizontal Orientation ◽  
Wide Range ◽  
Planar Electrodes ◽  
The Individual

An electrically tunable-focusing liquid crystal (LC) microlens array exhibiting a wide-range tunable focal length is proposed. The lower substrate has strip indium tin oxide (ITO) electrodes, the upper substrate has periodic ITO electrodes with a certain gap coated on the inner surface., and an LC microlens is generated between the two strip electrodes. For each LC microlens, the gap between the top planar electrodes is directly above the center of the microlens. Unlike the conventional LC lens, the individual LC microlens is not coated with ITO electrodes on the central part of its upper and lower substrates, which helps to maintain the LC’s horizontal orientation. In the voltage-off state, the focal length of the microlens array is infinity because of the homogeneous LC alignment. At a given operating voltage, an ideal gradient refractive index distribution is induced over the homogeneous LC layer, which leads to the focusing effect. The simulation result shows that the focal length of the LC microlens could be gradually drawn to 0.381 mm with a change of voltage.

High contrast ratio of a vertically aligned liquid crystal cell using photocrosslinking alignment

2002 ◽  
Vol 29 (6) ◽  
pp. 843-848 ◽  
Author(s):  
Hyun-Wuk Kim ◽  
Kyung-Soo Choi ◽  
Jin-Yool Kim ◽  
Tae-Min Kim ◽  
Jong-Duk Kim
Keyword(s):  
Liquid Crystal ◽  
Contrast Ratio ◽  
Liquid Crystal Cell ◽  
High Contrast ◽  
Crystal Cell ◽  
Vertically Aligned

scholarly journals Silicon oxides as alignment surfaces for vertically-aligned nematics in photonic devices

2014 ◽  
Vol 22 (2) ◽  
Author(s):  
E. Oton ◽  
S. López-Andrés ◽  
N. Bennis ◽  
J. Otón ◽  
M. Geday
Keyword(s):  
Liquid Crystal ◽  
Comparative Study ◽  
Contrast Ratio ◽  
Photonic Devices ◽  
Significant Rise ◽  
Liquid Crystal Alignment ◽  
Homeotropic Alignment ◽  
Vertically Aligned ◽  
Crystal Alignment ◽  
Inorganic Layers

AbstractA comparative study on alignment performance and microstructure of inorganic layers used for liquid crystal cell conditioning has been carried out. The study has focused on two specific materials, SiOx and SiO2, deposited under different conditions. The purpose was to establish a relationship between layer microstructure and liquid crystal alignment. The surface morphology has been studied by FESEM and AFM. An analysis on liquid crystal alignment, pretilt angle, response time, contrast ratio and the conditions to develop backflow effect (significant rise time increase due to pure homeotropic alignment) on vertically-aligned nematic cells has been carried out. A technique to overcome the presence of backflow has been identified. The full comparative study of SiOx and SiO2 layer properties and their influence over liquid crystal alignment and electrooptic response is presented.

Effects of carbon nanotubes on electro-optic characteristics in vertically aligned liquid crystal display

2013 ◽  
Vol 40 (9) ◽  
pp. 1202-1208 ◽  
Author(s):  
Young Jin Lim ◽  
Surjya Sarathi Bhattacharyya ◽  
Weiwei Tie ◽  
Hye Ryung Park ◽  
Young Hee Lee ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Crystal ◽  
Liquid Crystal Display ◽  
Electro Optic ◽  
Vertically Aligned

Effect of dye on electro-optic behavior of vertically aligned liquid crystal display cell

2020 ◽  
Author(s):  
Chinky ◽  
Ankit Rai Dogra ◽  
Vandna Sharma ◽  
Ridhima Gahrotra ◽  
Praveen Malik ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystal Display ◽  
Electro Optic ◽  
Vertically Aligned
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