scholarly journals Large Scale Liquid Crystal Device with Graphene-based Electrodes

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Stefan Petrov ◽  
Vera Marinova ◽  
Shiuan Huei Lin ◽  
Chia Ming Chang ◽  
Yi Hsin Lin ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Large Scale ◽  
Contrast Ratio ◽  
Optical Transmittance ◽  
Device Fabrication ◽  
Electrical Measurements ◽  
Liquid Crystal Device ◽  
Glass Substrates ◽  
Alignment Technique ◽  
Photo Alignment

AbstractThe new generation Liquid-Crystal Displays (LCDs) will play a key role in modern display industry thus the requirements concerning the response time, power consumption, viewing angles, contrast ratio and easy production stay beyond challenging. In this paper we demonstrate fabrication of large scale liquid crystal device with graphene-based electrodes using a photo-alignment technique. The quality of graphene layer, grown by low pressure CVD method and transferred on the glass substrates was characterized by several techniques: Raman spectroscopy, optical transmittance and electrical measurements. A photo-alignment method instead of commonly used mechanical rubbing technique was used to protect the graphene surface and prevent its partial deattachment from the glass substrates by coating a polyimide layer on the top of graphene. Measured modulation characteristics reveal that the photo-alignment technique possesses great potential for next generation graphene - based LC device fabrication.

Au-Based Transparent Conductors for Window Applications: Effect of Substrate Material

2010 ◽  
Vol 75 ◽  
pp. 25-30
Author(s):  
Pia C. Lansåker ◽  
Klas Gunnarsson ◽  
Arne Roos ◽  
Gunnar A. Niklasson ◽  
Claes Goran Granqvist
Keyword(s):  
Large Scale ◽  
Near Infrared ◽  
Film Growth ◽  
Film Formation ◽  
Optical Transmittance ◽  
Substrate Material ◽  
Transparent Conductors ◽  
Glass Substrates ◽  
Au Film ◽  
Window Applications

Thin films of Au were made by sputter deposition onto glass substrates with and without transparent and electrically conducting layers of SnO2:In. The Au films were up to ~11 nm in thickness and covered the range for thin film growth from discrete islands, via large scale coalescence and formation of a meandering conducting network, to the formation of a more or less “holey” film. Scanning electron microscopy and atomic force microscopy showed that the SnO2:In films were considerably rougher than the glass itself. This roughness influenced the Au film formation so that large scale coalescence set in at a somewhat larger thickness for films on SnO2:In than on glass. Measurements of spectral optical transmittance and electrical resistance could be reconciled with impeded Au film formation on the SnO2:In layer, leading to pronounced “plateaus” in the near infrared optical properties for Au films on SnO2:In and an accompanying change from such two-layer films having a lower resistance than the single gold film at thicknesses below large scale coalescence to the opposite behavior for larger film thicknesses.

scholarly journals Photo-Aligned Ferroelectric Liquid Crystal Devices with Novel Electro-Optic Characteristics

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 563
Author(s):  
Vladimir Chigrinov ◽  
Qi Guo ◽  
Aleksey Kudreyko
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Berry Phase ◽  
Photonic Devices ◽  
Ferroelectric Liquid Crystal ◽  
Optical Elements ◽  
Ferroelectric Liquid Crystals ◽  
Liquid Crystal Devices ◽  
Alignment Technique ◽  
Photo Alignment

This paper examines different applications of ferroelectric liquid crystal devices based on photo-alignment. Successful application of the photo-alignment technique is considered to be a critical breakthrough. A variety of display and photonic devices with azo dye aligned ferroelectric liquid crystals is presented: smart glasses, liquid crystal Pancharatnam–Berry phase optical elements, 2D/3D switchable lenses, and laser therapy devices. Comparison of electro-optical behavior of ferroelectric liquid crystals is described considering the performance of devices. This paper facilitates the optimization of device design, and broadens the possible applications in the display and photonic area.

Photo-Alignment Effect in Liquid-Crystal Films Containing Nanoparticles and Azo-Dye

2010 ◽  
Vol 428-429 ◽  
pp. 276-279 ◽  
Author(s):  
Tsung Hsien Lin ◽  
Wen Zheng Chen
Keyword(s):  
Liquid Crystal ◽  
Azo Dye ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Alignment Effect ◽  
Practical Applications ◽  
Liquid Crystal Films ◽  
Crystal Film ◽  
Crystal Films ◽  
Alignment Technique ◽  
Photo Alignment

This work reports the photo-alignment effect in a liquid-crystal film doped with nanoparticles and azo-dye. Vertical alignment induced by the nanoparticles polyhedral oligomeric silsesquioxanes (POSS) can be switched to homogeneous alignment by the absorption of photo-excited azo-dye. Both electro-optical and surface properties are analyzed to verify this effect. Using this photo-alignment technique in nanoparticle- and azo-dye-doped liquid crystal, the phase grating is also demonstrated. The diffraction efficiency is related to the polarization of the probe light and can be controlled by applying voltage. Both nanoparticle- and azo-dye-induced vertical and homogeneous alignments are non-contact aligning methods. Thus, the technique based on dopant-induced alignment has potential for practical applications.

scholarly journals Flexible Bistable Smectic-A Liquid Crystal Device Using Photolithography and Photoinduced Phase Separation

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Yang Lu ◽  
Jinbao Guo ◽  
Hao Wang ◽  
Jie Wei
Keyword(s):  
Liquid Crystal ◽  
Phase Separation ◽  
Contrast Ratio ◽  
Polymer Layer ◽  
Mechanical Pressure ◽  
Flexible Display ◽  
Liquid Crystal Device ◽  
Smectic A ◽  
Polymer Wall ◽  
Excellent Stability

A flexible bistable smectic-A liquid crystal (SmA LC) device using pixel-isolated mode was demonstrated, in which SmA LC molecules were isolated in pixels by vertical polymer wall and horizontal polymer layer. The above microstructure was achieved by using ultraviolet (UV) photolithography and photoinduced phase separation. The polymer wall was fabricated by photolithography, and then the SmA LC was encapsulated in pixels between polymer wall through UV-induced phase separation, in which the polymer wall acts as supporting structure from mechanical pressure and maintains the cell gap from bending, and the polymer layer acts as adhesive for tight attachment of two substrates. The results demonstrated that all the intrinsic bistable properties of the SmA LC are preserved, and good electrooptical characteristics such as high contrast ratio and excellent stability of the bistable states were characterized. This kind of SmA bistable flexible display has high potential to be used as electronic paper, smart switchable reflective windows, and so forth.

RAS - a new process control tool in liquid crystal device fabrication

2002 ◽  
Vol 35 (11) ◽  
pp. L41-L43 ◽  
Author(s):  
B F Macdonald ◽  
W Zheng ◽  
R J Cole ◽  
I Underwood
Keyword(s):  
Liquid Crystal ◽  
Process Control ◽  
Device Fabrication ◽  
Liquid Crystal Device ◽  
New Process ◽  
Control Tool

Low-driving-voltage, polarizer-free, scattering-controllable liquid crystal device based on randomly patterned photo-alignment

2020 ◽  
Vol 45 (13) ◽  
pp. 3697 ◽  
Author(s):  
Yide Yuan ◽  
Fan Fan ◽  
Chenxiang Zhao ◽  
Hoi-Sing Kwok ◽  
Martin Schadt
Keyword(s):  
Liquid Crystal ◽  
Driving Voltage ◽  
Liquid Crystal Device ◽  
Photo Alignment
Sign in / Sign up

Export Citation Format

Share Document