Study of the Relationships Between Optical and Physical Properties for Nanostructure TiO2 Thin Film

Pulsed Laser Deposition (PLD) technique was performed to deposit the pure Titanium oxide (TiO2) nanoparticles on the glass substrate of temp. (100 - 400°C), using the doubled frequency of Nd: YAG laser wavelength of 532nm at (10) Hz rate, 10 nanosecond duration pulses and a constant laser energy 800 mJ. The optical measurements obtained by UV-Vis transmittance on deposited TiO2 films indicate the highest transparency in the visible wavelength region with an average transmittance of 80%. Estimated the relationship between the refractive index of TiO2 thin films with substrate temperature was n = 2.49 at 400 oC. Moreover, the calculated empirical relation between the energy gap and refractive index have similar to the work results.

Стабильность функциональных характеристик прозрачных электродов на основе трехслойной структуры ZnO : Ga/Ag/ZnO : Ga

Since to the stability of the functional properties of a transparent conducting three-layer structure ZnO:Ga/Ag/ZnO:Ga is important for practical application, we studied its long-term durability and thermal stability in air environment. It has been demonstrated that after prolonged interaction with the air environment at room temperature (~ 1000 h) and further heat treatment in air at temperatures up to 450 ° C (up to 10 h), the three-layer structure retains its integrity and is characterized by a low sheet resistance Rs = 2.8 Ω/sq at average transmittance in the visible range Tav of 82.1%.

Preparation of Double-Layer Crossed Silver Nanowire Film and Its Application to OLED

Ordered silver nanowire (AgNW) film can effectively reduce the density of nodes, reduce the roughness of the film, and increase its conductivity and transmittance. In this paper, a double-layer crossed AgNW grid film was prepared by the auxiliary stirring method. The average transmittance of the double-layer crossed AgNW grid film was found to be 80% in the 400–1000 nm band, with a square resistance of 35 Ω/sq. As a transparent conductive anode material, the ordered AgNW film was applied to fabricate a flexible green organic light-emitting diode (OLED). The experimental results showed that the threshold voltage of the OLED was only 5 V and the maximum luminance was 1500 cd/m2.

Designing a Color Filter with High Overall Transmittance for Improving the Color Accuracy of Digital Cameras

Previously improved color accuracy of a given digital camera was achieved by carefully designing the spectral transmittance of a color filter to be placed in front of the camera. Specifically, the filter is designed in a way that the spectral sensitivities of the camera after filtering are approximately linearly related to the color matching functions (or tristimulus values) of the human visual system. To avoid filters that absorbed too much light, the optimization could incorporate a minimum per wavelength transmittance constraint. In this paper, we change the optimization so that the overall filter transmittance is bounded, i.e. we solve for the filter that (for a uniform white light) transmits (say) 50% of the light. Experiments demonstrate that these filters continue to solve the color correction problem (they make cameras much more colorimetric). Significantly, the optimal filters by restraining the average transmittance can deliver a further 10% improvement in terms of color accuracy compared to the prior art of bounding the low transmittance.

Edible Biopolymers-Based Materials for Food Applications—The Eco Alternative to Conventional Synthetic Packaging

The problem of waste generated by packaging obtained from conventional synthetic materials, often multilayer, has become more and more pressing with increasing consumption. In this context, nature and humanity have suffered the most. In order to address this phenomenon, global and European organizations have launched and promoted programs and strategies. Replacing petroleum-based packaging with biopolymer packaging has proven to be a real alternative. Thus, the substitution of plastics with biodegradable, non-toxic, edible materials, which can be obtained from marine or agro-industrial waste, is of interest. In the present study, we aimed to develop natural edible materials, obtained entirely from biopolymers such as agar and sodium alginate and plasticized with glycerol and water. Designed to be used for food and food supplements packaging, they can be completely solubilized before consumption. The films were developed through a casting method and were tested in order to identify the physical, optical, and solubility properties. According to the results, the most suitable composition for use as a hydrosoluble packaging material contains agar:alginate:glycerol in a 2:1:1 ratio. The microstructure indicates a homogeneous film, with low roughness values (Rz = 12.65 ± 1.12 µm), high luminosity (92.63), above-average transmittance (T = 51.70%), and low opacity (6.30 A* mm−1). The obtained results are of interest and highlight the possibility of substituting intensely polluting materials with those based on biopolymers.

Fabrication and characterization of flexible hybrid transparent electrodes with broadband transparency

In this study, indium-zinc oxide (IZO)/silver (Ag)/IZO (ZAZ) flexible transparent electrodes were prepared on polyethylene terephthalate substrate using radio frequency sputtering technique. Experimental results showed that when the Ag film transited from semi-continuous state to continuous state, the ZAZ electrode exhibited high optoelectronic performance. The best ZAZ sample had a quite wide range of high transmittance and an average transmittance of 78.9% in visible light region, and sheet resistance of [Formula: see text]/sq and a Haacke Index of [Formula: see text]. The bending test revealed that the [Formula: see text] (change in sheet resistance) of ZAZ electrodes after 1000 bends was still less than 25% while the electrical properties of IZO films deteriorated after only 100 bending tests.

Phylogenetic comparison of egg transparency in ascidians by hyperspectral imaging

The transparency of animals is an important biological feature. Ascidian eggs have various degrees of transparency, but this characteristic has not yet been measured quantitatively and comprehensively. In this study, we established a method for evaluating the transparency of eggs to first characterize the transparency of ascidian eggs across different species and to infer a phylogenetic relationship among multiple taxa in the class Ascidiacea. We measured the transmittance of 199 eggs from 21 individuals using a hyperspectral camera. The spectrum of the visual range of wavelengths (400–760 nm) varied among individuals and we calculated each average transmittance of the visual range as bio-transparency. When combined with phylogenetic analysis based on the nuclear 18S rRNA and the mitochondrial cytochrome c oxidase subunit I gene sequences, the bio-transparencies of 13 species were derived from four different families: Ascidiidae, Cionidae, Pyuridae, and Styelidae. The bio-transparency varied 10–90% and likely evolved independently in each family. Ascidiella aspersa showed extremely high (88.0 ± 1.6%) bio-transparency in eggs that was maintained in the “invisible” larva. In addition, it was indicated that species of the Ascidiidae family may have a phylogenetic constraint of egg transparency.

A Multi-Position Drum-Type Assembly for Simultaneous Film Deposition at Different Temperatures in a Single Sputter Cycle–Application to ITO Thin Films

The design of a multi-position drum-type assembly (MPDTA) for heating and positioning substrates with the possibility of individually setting and controlling the temperature of each substrate, which is applicable for laboratory-type sputtering setups, is described. The above design provides the possibility of the simultaneous deposition of thin films under identical conditions on several substrates at different temperatures, making it possible to explore the temperature dependences of the films’ morphology, structure, and functional characteristics in one single vacuum deposition cycle. As a case study, the possibility of investigating such dependencies for the magnetron deposition of transparent conducting indium–tin oxide (ITO) thin films was demonstrated using the MPDTA. The investigation results revealed that the functional performances of deposited ITO thin films (resistivity and average transmittance in the visible range) improved with increasing the substrate temperature, reaching values of 1.5 × 10−4 Ω·cm and over 80%, respectively, at 300 °C.

Impact of Thickness and Substrate on Optical Properties of Zno Thin Films

During the last decades, ZnO has emerged as the most promising material in optoelectronic and optical applications in the visible region as well as in the infrared and UV region. It is because of the broad direct band gap of 3.37 eV at ambient temperature and high exciton binding energy of 60 meV allowing it to utilize the ultraviolet region. In this investigation, the optical characteristics of ZnO thin film of various thicknesses (300 nm, 600 nm, 900 nm) deposited on Quartz, Fused silica and Sapphire have been studied as a function of wavelength and photon energy. To obtain this, the equations for thin film have been derived, simulated and visualized by Matlab coding language. It is observed that with the increase in the photon energy, the refractive index and extinction coefficient show an increasing tendency. The results represent that among three substrates Fused silica has the lowest refractive index, reflectance and absorbance. In the visible region, the transmission spectra show that the average transmittance of all films is 85%-95%, which is superior for solar continuums. The performance of Fused silica as transparent conducting material is better than other substrates. The present investigation might provide an environment friendly and low cost material for optoelectronic and solar cell devices. Bangladesh Journal of Physics, 27(1), 59-68, June 2020

Cu(In,Ga)Se2 Solar Cells Integrated with Subwavelength Structured Cover Glass Fabricated by One-Step Self-Masked Etching

We report an anti-reflective cover glass for Cu(In,Ga)Se2 (CIGS) thin film solar cells. Subwavelength structures (SWSs) were fabricated on top of a cover glass using one-step self-masked etching. The etching method resulted in dense whiskers with high aspect ratio. The produced structure exhibited excellent anti-reflective properties over a broad wavelength range, from the ultraviolet to the near infrared. Compared to a flat-surface glass, the average transmittance of the glass integrated with the SWSs improved from 92.4% to 95.2%. When the cover glass integrated with the SWSs was mounted onto the top of a CIGS device, the short-circuit current and the efficiency of the solar cell were enhanced by 4.38 and 6%, respectively, compared with a CIGS solar cell without cover glass.