The alignment of nematic liquid crystal by the Ti layer processed by nonlinear laser lithography

2018-01-01
Pavlov, Ihor
Dobrovolskiy, Andrii
Kadan, Viktor
Blonskiy, Ivan
Ilday, Fatih O.
Kazantseva, Zoya
Gvozdovskyy, Igor
It is well known that the alignment of liquid crystals (LCs) can be realised by rubbing or photoalignment technologies. Recently, nonlinear laser lithography (NLL) was introduced as a fast, relatively low-cost method for large area nano-grating fabrication based on laser-induced periodic surface structuring. In this letter for the first time, the usage of the NLL as a perspective method of the alignment of nematics was presented. By NLL, nanogrooves with about 0.92m period were formed on Ti layer. The nanostructured Ti layer (NSTL) was coated with oxidianiline-polyimide film with annealing of the polymer followed without any further processing. Aligning properties of NSTLs were examined with combined twist LC cell. The dependencies of the twist angle of LC cells and azimuthal anchoring energy (AE) of layers on scanning speed and power of laser beam during processing of the Ti layer were the focus of our studies as well. The maximum azimuthal AE, obtained for pure NSTL, is comparable with photoalignment technology. It was found that the deposition of polyimide film on NSTL leads to the gain effect of the azimuthal AE. Also, atomic force microscopy(AFM) study of aligning surfaces was carried out.
LIQUID CRYSTALS

Suggestions

Influence of photonic excitations on the electrical parameters of TlInS2 crystals
QASRAWI, ATEF FAYEZ HASAN; Hasanlı, Nızamı (Wiley, 2010-04-01)
The photo-excitation effect on the current transport mechanism in TlInS2 crystals has been studied by means of dark and illuminated conductivity measurements. The temperature-dependent electrical conductivity analysis in the temperature region of 110-340 K revealed the domination of the thermionic emission and the thermally assisted variable range hopping (VRH) of charge carriers above and below 160 K, respectively. Above 160 K, the conductivity activation energies in the dark are found to be 0.28 and 0.15 ...
A novel experimental and density functional theory study on palladium and nitrogen doped few layer graphene surface towards glucose adsorption and electrooxidation
Caglar, Aykut; Duzenli, Derya; Önal, Işık; Tezsevin, Ilker; Sahin, Ozlem; Demir Kıvrak, Hilal (Elsevier BV, 2021-03-01)
At present, few layer graphene (G) and nitrogen doped few layer graphene (N doped-G) are firstly coated on Cu foil via chemical vapor deposition (CVD) method and G and N doped-G coated Cu foil is transferred to the indium tin oxide (ITO) substrate surface to obtain electrodes. Pd metal is electrodeposited onto the N doped-G/ITO electrode (Pd-N doped-G/ITO). Pd-N doped-G/ITO electrode are characterized with advanced surface characterization methods such as Raman spectroscopy and SEM-EDX. Characterization res...
Analysis of the Hall effect in TlGaTe2 single crystals
QASRAWI, ATEF FAYEZ HASAN; Hasanlı, Nızamı (IOP Publishing, 2009-06-10)
The electrical resistivity and Hall coefficient of p-type TlGaTe2 crystals were measured in the temperature range of 110-320 K. The electrical resistivity, charge carrier density and Hall mobility data for the crystals have been analyzed by means of existing theories and models to determine the extrinsic energy levels, the carrier effective mass, the donor and acceptor concentrations and the dominant scattering mechanism in the crystal as well. The analysis of the temperature-dependent electrical resistivit...
Investigation of carrier scattering mechanisms in TIInS2 single crystals by Hall effect measurements
Qasrawi, AF; Hasanlı, Nızamı (Wiley, 2004-05-01)
TlInS2 single crystals are studied through the conductivity and Hall effect measurements in the temperature regions of 100-400 and 170-400 K, respectively. An anomalous behavior of Hall voltage, which changes sign below 315 K, is interpreted through the existence of deep donor impurity levels that behave as acceptor levels when are empty. The hole and electron mobility are limited by the hole- and electron-phonon short range interactions scattering above and below 315 K, respectively. An energy level of 35 ...
Determination of deep trapping center parameters in as-grown Tl2Ga2S3Se layered crystals
YILDIRIM, TACETTİN; Hasanlı, Nızamı (Elsevier BV, 2009-09-01)
Thermally stimulated current measurements were carried out on as-grown Tl2Ga2S3Se layered single crystals. The investigations were performed in temperatures ranging from 10 to 320 K with heating rates of 0.6-1.2 K s(-1). The analysis of the data revealed the hole trap level located at 498 meV. The activation energies of the traps have been determined using various methods of analysis, and they agree with each other. The calculation for these traps yielded 2.1 x 10(-18) cm(2) for capture cross-section and 2....
Citation Formats
I. Pavlov et al., “The alignment of nematic liquid crystal by the Ti layer processed by nonlinear laser lithography,” LIQUID CRYSTALS, pp. 1265–1271, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/56165.