High-quality alignment of nematic liquid crystals using periodic nanostructures created by nonlinear laser lithography

Date

2018-10-01

Author

Pavlov, Ihor
Dobrovolskiy, A. M.
Kadan, V. M.
Blonskiy, I. V.
Kazantseva, Z. I.
Gvozdovskyy, I. A.

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

175
views

0
downloads

It is well known that today two main and well studied methods for alignment of liquid crystals has been used, namely: rubbing and photoalignment technologies, that lead to the change of anisotropic properties of aligning layers and long-range interaction of the liquid crystal molecules in a mesophase. In this manuscript, we use the nonlinear laser lithography technique, which was recently presented as a fast, relatively low-cost method for a large area micro and nanogrooves fabrication based on laser-induced periodic surface structuring, as a new perspective method of the alignment of nematic liquid crystals. 920 nm periodic grooves were formed on a Ti layer processed by means of the nonlinear laser lithography and studied as an aligning layer. Aligning properties of the periodic structures of Ti layers were examined by using a combined twist LC cell. In addition, the layer of the nanostructured Ti was coated with an oxidianiline-polyimide film with annealing of the polymer film followed without any further processing. The dependence of the twist angle of LC cells on a scanning speed and power of laser beam during processing of the Ti layer was studied. The azimuthal anchoring energy of Ti layers with a periodic nanostructure was calculated. The maximum azimuthal anchoring energy for the nanostructured Ti layer was about 4.6 x 10(-5) J/m(2), which is comparable to the photoalignment technology. It was found that after the deposition of a polyimide film on the periodic nanostructured Ti layer, the gain effect of the azimuthal anchoring energy to -1 x 10(-4) J/m(2) is observed. Also, AFM study of aligning surfaces was carried out.

Subject Keywords

Aligning layers, Azimuthal anchoring energy, Polyimide, Nematic liquid crystals, Nonlinear laser lithography, Nanostructured titanium layers

URI

https://hdl.handle.net/11511/56218

Journal

JOURNAL OF MOLECULAR LIQUIDS

DOI

https://doi.org/10.1016/j.molliq.2018.02.058

Collections

Department of Physics, Article

Suggestions

OpenMETU
Core

Enhancement of Laser Damage Resistance at 1064 nm of High and Anti-Reflective Optical Multilayers by Tailoring the Electric Field Distribution and Post-Annealing Aydogdu, G. H.; Batman, H.; Cosar, M. B.; Ozhan, A. E. S. (2016-05-13) In this study, multilayer Ta2O5/SiO2 and HfO2/SiO2 films were deposited on glass substrates by ion beam sputtering and physical vapor deposition methods, respectively. The effect of electric field distribution and heat treatment of these oxide multilayers on laser damage resistance were investigated systematically. Optical performance was characterized by spectrophotometer. Electric field analysis and optic system design were performed by thin film design software. LIDT (laser-induced damage threshold) meas...
Use of gold nanoparticle containing poly (allylamine hydrochloride)/ poly (acrylic acid) multilayer films as sers substrates Kölemen, Birsu; Ertaş, Gülay; Erel Göktepe, İrem; Department of Chemistry (2015) Surface-enhanced Raman spectroscopy (SERS) is a surface sensitive vibrational spectroscopy technique that results in the enhancement of Raman scattering by molecules adsorbed on rough metal surfaces. It is a powerful, sensitive and non-destructive technique which is used in chemical, material and life sciences including biosensing, catalysis, spectroelectrochemistry, criminology, single molecule SERS applications and many others. Nanoparticle (NP) embedded multilayer films using Layer by Layer (LbL) techniq...
Computational Modeling of the Effects of Viscous Dissipation on Polymer Melt Flow Behavior During Injection Molding Process in Plane Channels Tutar, M.; Karakuş, Ali (2013-02-01) The present finite volume method based fluid flow solutions investigate the boundary-layer flow and heat transfer characteristics of polymer melt flow in a rectangular plane channel in the presence of the effect of viscous dissipation and heat transfer by considering the viscosity and density variations in the flow. For different inflow velocity boundary conditions and the injection polymer melt temperatures, the viscous dissipation effects on the velocity and temperature distributions are studied extensive...
Structural properties of a-Si films and their effect on aluminum induced crystallization Tankut, Aydin; Karaman, Mehmet; Ozkol, Engin; Canlı, Sedat; Turan, Raşit (2015-10-01) In this paper, we report the influence of the structural properties of amorphous silicon (a-Si) on its subsequent crystallization behavior via the aluminum induced crystallization (AIC) method. Two distinct a-Si deposition techniques, electron beam evaporation and plasma enhanced chemical vapor deposition (PECVD), are compared for their effect on the overall AIC kinetics as well as the properties of the final poly-crystalline (poly-Si) silicon film. Raman and FTIR spectroscopy results indicate that the PECV...
Tuning the electron beam evaporation parameters for the production of hole and electron transport layers for perovskite solar cells Coşar, Mustafa Bura; Özenbaş, Ahmet Macit; Department of Metallurgical and Materials Engineering (2019) This study evaluates the use of electron beam evaporation technique for the deposition of electron and hole transport layers for perovskite solar cells where cell productions were performed in n-i-p structure. NiO and TiO layers were studied for hole transport layer and TiO2 and Nb2O5 layers were deposited for electron transport purposes. To optimize the suitable evaporation parameters for efficient perovskite cell production, single layers of each material were deposited at different conditions of oxygen f...

Citation Formats

I. Pavlov, A. M. Dobrovolskiy, V. M. Kadan, I. V. Blonskiy, Z. I. Kazantseva, and I. A. Gvozdovskyy, “High-quality alignment of nematic liquid crystals using periodic nanostructures created by nonlinear laser lithography,” JOURNAL OF MOLECULAR LIQUIDS, pp. 212–221, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/56218.