RESUMO
It is common knowledge that using different oxygen contents in the working gas during sputtering deposition results in fabrication of indium zinc oxide (IZO) films with a wide range of optoelectronic properties. It is also important that high deposition temperature is not required to achieve excellent transparent electrode quality in the IZO films. Modulation of the oxygen content in the working gas during RF sputtering of IZO ceramic targets was used to deposit IZO-based multilayers in which the ultrathin IZO unit layers with high electron mobility (µ-IZO) alternate with ones characterized by high concentration of free electrons (n-IZO). As a result of optimizing the thicknesses of each type of unit layer, low-temperature 400 nm thick IZO multilayers with excellent transparent electrode quality, indicated by the low sheet resistance (R ≤ 8 Ω/sq.) with high transmittance in the visible range (T¯ > 83%) and a very flat multilayer surface, were obtained.
RESUMO
Composites in a wide concentration range of 0-0.6 wt% based on a nematic liquid crystal mixture and CdS quantum dots doped with manganese ions (Mn 6%) are presented. The effect of the CdS:Mn quantum dots on the phase diagram and electronic structure of composites was studied using differential scanning calorimetry and fluorescence analysis. Nonmonotonic concentration-dependent changes in the clearing point, which correlate with the fluorescence quenching behavior of the main CdS:Mn peak, were found. Dielectric spectroscopy and electro-optic studies revealed a corresponding increase in the dielectric permittivity anisotropy and birefringence in the 0.2-0.4 wt% range, where thermodynamic changes occur. The initiating factors behind this effect are supposed to be the self-assembly of quantum dots, and the distortion of the orientation order of liquid crystal molecules at a higher mass concentration of quantum dots.
RESUMO
Diffraction optical elements (DOE) are important elements of systems for images displaying and processing. The DOE materials with both positive and negative birefringence enhance performances and functionality of such systems. We have calculated the diffraction of rays passing through optically anisotropic grating with surface microrelief by using our original Exedeep software. At the first time the diffraction parameters for both transmitted and reflected TE- and TM-waves are calculated for materials with both positive and negative optical anisotropy. The simulation results are to be used to create DOE for the visible, UV, IR and THz ranges.
RESUMO
The phase retardation difference, ΔΦ, is calculated for hybrid liquid crystal (LC) cells as a function of LC pretilt angles, θ0(1), θ0(2), on the opposite substrates of the cell for the case of an arbitrary angle of light incidence in the range from 0 to 90°. An LC director configuration is suggested for its application in optical compensators. Design and fabrication methods of hybrid aligned nematic (HAN) cells with an arbitrary LC pretilt angle are described. The LC pretilt angle is measured in the HAN cells with a given planar or vertical LC alignment on one of the substrates.
RESUMO
Optical and electro-optical methods of liquid crystal (LC) director pretilt angle measurement are described for LC cells with homogeneous and inhomogeneous LC director distribution. The LC pretilt on both LC substrates can have the same or opposite direction. The phase retardation difference of both extraordinary and ordinary polarized rays passing through an LC cell with homogeneous and inhomogeneous LC director distribution has been calculated versus the LC pretilt angle θ(0) on the cell's substrates in the range 0≤θ(0)≤90°. The experimental procedure for phase retardation difference determination by measurement of the LC cell transmission between crossed polarizers for cells with LC tilted alignment is described. The method developed can also be used in optical compensator design.
