The process of creating a photosensitive structure with a double-distributed heterojunction based on a combination of fullerene and non-fullerene acceptors (PC71BM and ITIC-F) is described in this work. P3HT was used as the donor in both layers. The spectral photosensitivity response of the resulting FTO/P3HT:ITIC-F/P3HT:PC71BM/InGaSn structure covers a wide range of 470-980 nm. The peak photosensitivity of the structure reaches 40.98 mA/W, which is many times higher than the values for structures based on individual layers and a blend of all materials in one bulk heterojunction. The studies and measurements show that such a structure can be used in optics and electronics to detect radiation in the visible and near-IR ranges. In addition, the principle of creating a double-distributed heterojunction structure used in this study can be applied to other organic materials to obtain previously unattainable performance levels.

Triple-cation perovskite solar cells, such as Cs0.05(FA0.83MA0.17)0.95Pb(I0.83Br0.17)3 (hereinafter referred to as CsFAMA) have high efficiency (>26%), but their stability is limited by phase segregation and defects at grain boundaries. In this work, the effect of formic acid (HCOOH) on suppressing the degradation of perovskite films is investigated. It is shown that the addition of HCOOH to the precursor solution reduces the size of colloidal particles by 90%, which contributes to the formation of highly homogeneous films with a photoluminescence intensity deviation of ≤3%. Structural analysis and dynamic light scattering measurements confirmed that HCOOH suppresses iodide oxidation and cation deprotonation, reducing the defect density. Aging tests (ISOS-D) demonstrated an increase in the T80 lifetime (time to 80% efficiency decline) from 158 to 320 days for the modified cells under ambient conditions at room temperature and 40% relative humidity. The obtained results indicate a key role of HCOOH in stabilizing CsFAMA perovskite by controlling colloidal dynamics and defect passivation, which opens up prospects for the creation of commercially viable PSCs.

The general-purpose polymers formation issues are solved using micro- and nanoelectronic technologies of new generation, for example a nanoimprint lithography. One of its subspecies, soft lithography, includes topology formation using soft master die fabricated by hard mold imprint. Therefore, engineering study of possibility of hard molds self-dependent fabrication for the purposes of optoelectronic data bus formation for new generation printed circuit boards using general-purpose polymer materials is a priority. In this work, to rationalize the purchasing cost of an expensive hard mold of soft lithography, an original technological process for a hard mold fabrication based on the SU-8 photoresist has been developed and implemented. During the performing of the proposed technological process, the reason for the negative slope (T-topping) formation of soft lithography hard mold walls made of SU-8 photoresist was determined. A series of cut-off UV filters for optical wavelengths less than 350 nm has been developed and fabricated to eliminate T-topping. Based on the UV radiation intensity experimental measurements data from the i-line mercury lamp of the automated alignment and exposure system EVG620 NT, the UV radiation intensity attenuation dependences on the functional layer thickness of the developed optical UV filter for 365 and 400 nm wavelengths are plotted. The developed UV filters application effectiveness has been proven due to T-topping elimination during the technological process of producing the soft lithography hard mold test topology. The use of soft lithography will make it possible in the future to create a new generation printed circuit boards with a built-in optoelectronic data bus in the form of a polymer planar optical waveguides array and optical input / output elements.

Precise adaptation of the greenhouse lighting spectrum to basic photophysiological processes can effectively and directionally stimulate plant growth and development. The optimal spectrum depends on the plant species and the stage of development and could be assessed empirically. The aim of this study is to determine the LED illumination spectrum that provides a significant improvement in the growth rate and accumulation of biologically active compounds for basil plants (Ocimum basilicum L.) under hydroponic cultivation compared to more traditional lighting sources. The following light sources with various emission spectra were used: an LED lamp within a spectral range of 400–800 nm (B:G:R 15%:5%:80%); a high-pressure sodium lamp (HPS) (B:G:R 5%:45%:50%); a compact fluorescent lamp (B:G:R 20%:40%:40%); a grow LED strip (B:G:R 15%:40%:45%); a white LED lamp (B:G:R 30%:45%:25%); a customized LED lighting setup in color ratios 100%B, 75%B + 25%R, 50%B + 50%R, 25%B + 75%R, 100%R, and natural lighting. A photosynthetic photon flux density (PPFD) of 150 μmol∙m−2∙s−1 was provided with all the sources. It was demonstrated reliably that employing the LED strip as an illumination device gives a 112% increase in basil plant yield compared to the HPS; the transpiration coefficient for the LED strip is six times lower than for the HPS. The content of flavonoids in the basil aerial parts on the 30th, 50th, and 70th days of development is 3.2 times higher than for the HPS; the metabolite composition is also more uniform for LED strip lighting.

Introduction . The problem of increasing the efficiency of existing photodetectors and creating their new types attracts much research attention. Among new photodetector types are photosensitive structures based on cascade concentrators, whose operational principle involves the absorption of optical radiation followed by its reemission at a longer wavelength and radiation concentration onto a highly efficient small-area photodetector. The absorption and re-emission spectra of each cascade layer depend on the characteristics of the material used. Сolloidal quantum dots are among the most promising materials for cascade layers due to their manufacturing technology, which provides for accurate control over the photoluminescence maximum position. It seems highly relevant to develop and to study photosensitive structures with cascade concentrators of various shapes based on CdS, CdSe/ZnS, and PbS colloidal quantum dots. Aim . To develop photosensitive structures with a wide-range sensitivity spectrum based on concentrators containing arrays of metal chalcogenide CQDs and to study their characteristics. Materials and methods . Cascade photosensitive structures were manufactured based on layers made of polymethyl methacrylate and layers of colloidal quantum dots embedded in a polystyrene matrix. Results . Three-layer concentrators were manufactured with different colloidal quantum dots in each concentrator layers. A 22 % increase in the output power was observed for a three-layer cascade structure based on different cascade layer materials compared to a similar structure using a single layer concentrator. Conclusion . The conducted studies showed an increase in the efficiency of photosensitive structures with a cascade concentrator based on colloidal quantum dots of various types (CdS, CdSe/ZnS, and PbS) in the cascade layers.

Experimental samples of single-crystal silicon with hole conductivity doped with boron (KDB-12) and with electronic conductivity doped with phosphorus (KEF-4.5) were studied using the C–V method of postoperative control. On the original KEF-4.5 and KDB-12 wafers, a dielectric layer of silicon dioxide SiO2 was grown. Next, the near-surface layer was doped with phosphorus or boron by ion implantation with the type of conductivity corresponding to the substrate. Postoperative control of the dose of impurity atoms embedded by ion implantation was carried out according to capacitance–voltage characteristics. The impurity distribution profiles for the same sample obtained at different points, as well as for different samples with the same implanted dose, differed slightly. The calculation of the dose of implanted ions and the relative error showed a high accuracy of control of the ion implantation process by measuring the capacitance–voltage characteristics. The relative measurement error when compared with the given dose did not exceed 10

Studies of structures, including a hole-conducting epitaxial layer, doped with boron (KDB – 12), and an electron-conducting layer, doped with phosphorus (KEF – 4,5), are presented. A dielectric layer of silicon dioxide SiO2, from 97 nm to 117 nm thick, as measured using ellipsometry, was grown on the wafers. Then, the subsurface layer was doped with phosphorus or boron using ion implantation, with conductivity type corresponding to the substrate. The postoperative control of dopant atoms dose, embedded by ion implantation, was carried out using the capacitance-voltage characteristics. Dopant distribution profiles for the same sample, as well as for different samples with the same implanted dopant dose differed insignificantly. The relative error of the measurements, as compared to the preassigned dose, was no higher than 10 %. The dose parameter deviation higher than 5 % was observed in samples with the preassigned ion dose close to the maximum detectable dose of implanted ions, allowed for this method.

Introduction. In view of growing environmental concerns, innovative solutions to ensure electrical energy supply to various devices and systems are required. As a result, renewable energy sources, including those based on solar energy, are attracting much attention. In this context, the development of a Wi-Fi router powered by modern photovoltaic converters seems to be a relevant research task.Aim. Development of a Wi-Fi router powered by modern photovoltaic converters.Materials and methods. The proposed system was developed on the basis of a Wi-Fi router YF360-H and a photovoltaic cell HVL-105/O.Results. Calculations of the developed photovoltaic system were performed; volt-ampere and watt-ampere characteristics of the solar panel were investigated. The solar panel power supply circuit was developed, with the conversion efficiency in the working area achieving 90 %. The capacity of the external battery ensuring the system's autonomous operation for 7 days was determined. A modeling experiment in the MATLAB environment demonstrated the high efficiency of the developed system.Conclusion. According to the conducted calculations, a HVL-105/O photovoltaic cell can be used to power a Wi-Fi router YF360-H under the weather conditions considered most unfavorable for solar cells.

Introduction. Light-emitting diode (LED) irradiation is widely used in various spheres of human activity, including agriculture. Due to the growing urban population and aggravating environmental situation, the problem of high-quality food provision is increasingly attracting research attention. In this context, it is important to develop energy-efficient optical systems for ensuring optimal irradiation conditions for accelerating the growth of various types of plants and improving the quality of products in autonomous agro-industrial complexes.Aim. Determination of an optimal spectral radiation composition of a phytolamp consisting of LEDs based on AlGalnP (660 and 730 nm) and InGaN (440 nm), as well as phyto-LEDs (400. _ .800 nm), to stimulate the growth and development of tomato and carrot sprouts at the germination stage. Calculation of the LED optical power and photosynthetic photon flux density (PPFD).Materials and methods. Experiments were carried out to study the influence of visible radiation of different quality and quantity on the development parameters of carrot and tomato seeds, including germination energy, the appearance of cotyledon and primary leaves, seed germination, average hypocotyl and root length. Optimal spectral composition and radiation power parameters ensuring effective growth of plants were determined.Results. Additional 660-nm irradiation of tomato sprouts at the germination stage was shown to exhibit a positive effect on germination, average sprout length and root development. The best results of carrot germination and development were achieved when irradiated with short-wavelength light (PPFD 243 µmol∙s–1∙m–2). Irradiation of ~ 170 µmol∙s–1∙m–2 blue and 86 µmol∙s–1∙m–2 red light was found to be effective for enhancing carrot cultivation.Conclusion. The developed irradiation schemes can be used to vary the spectral radiation composition and PPFD at different stages of crop growth and development, thereby increasing yields and reducing energy costs. In the future, this technology can be used in space research, where high energy efficiency is fundamental.

Abstract—Two approaches are used to form organic photosensitive structures. In the first of these, layered photoactive elements are created, in which active layers are deposited successively and have a sharp heterointerface. The second approach is employed in this study, which is based on the formation of a distributed (bulk) heterojunction between a metal phthalocyanine and fullerene in organic photosensitive structures. The influence exerted by the parameters with which the phthalocyanine:fullerene nanocomposite layer is formed on the optical and photoelectric characteristics of FTO/ZnPc:C60/C60/Al and FTO/ZnPc:C60/C60/BPhen/Al structures is considered. The samples under study are created by the method of thermal deposition in vacuum. In the experiment, four types of structures with different compositions of the active layers are fabricated. The configuration of the active layers is changed by varying the mass of the substance being evaporated. For the layer based on zinc phthalocyanine, the influence exerted by the substrate preheating temperature on the quality of the deposited layers is examined. It is found that the optimal temperature at which the layers are uniform and have the strongest absorption is 60°C. The absorption, transmission, and photosensitivity spectra of the samples are examined. The transmission spectra contain two pronounced strong-absorption regions, which correspond to fullerene and zinc phthalocyanine. It is shown that changing the fraction of the fullerene component affects the transport and photoelectric parameters of the nanocomposite layers and structures. The optimum configuration of the active layers is found to be ZnPc:C60/C60. It is shown that the introduction of an additional BPhen layer, which blocks holes and is sufficiently thin for electron transport, makes it possible to significantly raise the photoresponse and extend the sensitivity range of the structure under study.

Various surface reliefs of thin-film polyimide compositions structured by different methods using UV and IR radiation are considered for subsequent recommendations of their application in the light- and electro-addressable liquid crystalline spatiotemporal light modulators. Spectral measurements were carried out and contact wetting angles of the structured surface were determined. The atomic force analysis of the structured surface was also performed. Based on the obtained data, it is proposed that the performed product developments can be effectively used for the design of laser radiation modulators and converters, in which a liquid crystalline mesophase functions as an electro-optical modulating layer.

In this paper, we aim at debating the perspectives for plasmonic strain sensors which have attracted interest for the past five years. In particular, we strive to discuss the choice of strategy to increase the sensitivity, either by developing random or ordered assemblies of metallic nanotsructures.

Desulfurization of hydrocarbons is an important step in the processing of petroleum products, which requires an accurate and robust method for the sulfur-containing component evaluation. On the other hand, sulfur-containing heteroatomic hydrocarbon additives are harmful for people and the environment. Therefore, it is advantageous to conduct laboratory tests at low volumes to reduce doses of exposure of sulfur-containing vapors to the personnel. Microfluidics is an emerging platform that provides an advantage to operate with low volumes. The microfluidic dielectric spectroscopy approach is proposed in the current contribution as a platform for determination of the concentration of polar heteroatomic components in binary mixtures. The presence of heteroatomic components in petroleum products leads to a perceptible change in the dielectric properties of the blend. This paper shows the technological aspects for the microfluidic sensor chip design. It was successfully used to determine the concentration of thiophene (as a typical sulfur-containing hydrocarbon) in gasoline. We compare the commercially available solution with the developed microfluidic sensor. We demonstrate the developed microfluidic sensor chip that has a comparable sensitivity as a macroscopic commercial measurement cell but at the microscale. It is able to operate at 103 times reduced volume of liquid analyte, providing stable control of the sulfur-containing additive concentration. The obtained results are intended to be applied for lab monitoring of sulfur-containing components in petroleum products. (c) 2020 Author(s).

The paper considers the effect of fullerene concentration in active layers on the spectral characteristics of organic photosensitive structures based on the ZnPc:C60 system. The studied samples were created using the vacuum thermal evaporation method. Absorption, transmission, and photosensitivity spectra were studied for the created samples.

A study of the surface topography and optical characteristics of thin AlN films used as passivating and antireflection coatings deposited on n-GaAs (100) substrates by reactive ion-plasma sputtering is reported. It was found that the process conditions affect the structure and the optical characteristics of the films, which makes it possible to obtain coatings with prescribed parameters. An analysis of the results furnished by ellipsometry and atomic-force microscopy of the surface shows that the refractive index of the films is correlated with the surface structure.

The article investigates the effect of heating of the LEDs active region (AR) on the luminescence efficiency of LEDs of various spectral ranges. As a result of the work the method for contactless determination of the active LED region temperature with account the influence of the Stark effect was created. The method is based on the analysis of the long-wave part of the spectrum whose behavior primarily depends on the crystal temperature.

In this paper, high-speed planar waveguides of optoelectronic data bus are suggested replacing low-throughput backplane electrical interconnects. Optical polymer polydimethylsiloxane (PDMS) and cost-efficient soft lithography technology are proposed for optoelectronic bus fabrication. In accordance with polymer optoelectronic data bus fabrication process work-out results the chosen materials and technology applicability was confirmed. As an optoelectronic bus characteristics measurement results, 14 dB/cm propagation losses value was obtained by general use materials.

Structures based on AlInGaN solid solutions were studied. The types of defects in them and the corresponding emission bands of photoluminescence (PL) spectra were identified. It is possible to determine the concentration of defects in the structure from the ratio of the intensities of the emission line, corresponding to the width of the forbidden zone in GaN, and the emission lines associated with defects.

Abstract In this research we have created light-emitting structures that contain colloidal quantum dots of cadmium selenide in the active layer. To do so, we have used methods of vacuum thermal deposition and spin coating for the formation of organic layers. We have compared photo- and electroluminescence spectra of the structures, and have revealed necessary conditions for the creation of high quality layers.

AbstractA study of the surface topography and optical characteristics of thin AlN films used as passivating and antireflection coatings deposited on n -GaAs (100) substrates by reactive ion-plasma sputtering is reported. It was found that the process conditions affect the structure and the optical characteristics of the films, which makes it possible to obtain coatings with prescribed parameters. An analysis of the results furnished by ellipsometry and atomic-force microscopy of the surface shows that the refractive index of the films is correlated with the surface structure.