Uniform coverage of the absorber layer is crucial for the performance of perovskite-based optoelectronic devices. In this study methylammonium chloride (MACl) was introduced as an additive into the formamidinium lead mixed-halide (FAPbBr2Cl) perovskite. Perovskite films of pristine FAPbBr2Cl were synthesized using a traditional one-step spin-coating method under ambient conditions. In contrast, samples with the MACl additive were fabricated using a two-step spin-coating procedure with various annealing times. To evaluate the optoelectronic properties of the fabricated films, which serve as an indicator of film uniformity, photoluminescence, absorption and transmittance spectra were studied. The results indicate that the films containing the MACl additive possess higher uniformity, which can be attributed to enhanced crystallization and higher surface quality. It was confirmed that optimizing the annealing time is a critical factor for achieving high uniformity in perovskite films.

Agrophotonics is a field of science that uses radiation to control the agricultural organisms vital activity. The most important factor influencing the growth and development of plants is the spectral composition and radiation source power. The article presents the development of an energy-efficient phytotron for growing plants in controlled environmental conditions. A radiation source design is shown, which includes three-watt LEDs at the required wavelengths (370 nm, 445 nm, 520 nm, 660 nm, 730 nm). A control system consisting of a microcontroller and the necessary sensors connected to an external device (tablet) via a Wi-Fi module is presented.

Bulk heterojunction photosensitive structures for the visible and near-infrared ranges were fabricated and studied. The structures were based on the organic polymers Poly(3-hexylthiophene-2,5-diyl) (P3HT) and Poly{2,6´-4,8-di(5-ethylhexylthienyl)benzo[1,2-b;3,4-b]dithiophene-alt-5-dibutyloctyl-3,6-bis(5-thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4-dione} (PBDTT-DPP), which were used as donors, and a fullerene derivative – [6, 6]-Phenyl-C71-butyric acid methyl ester (PC71BM) which was employed as the acceptor. The influence of the substrate spin-coating speed on the uniformity of the fabricated active-layer films was studied. The optimal deposition rate was found to be 800 rpm for the P3HT:PC71BM blend and 1000 rpm for the PBDTT-DPP:PC71BM blend. The photoresponsivity spectra were investigated. The P3HT:PC71BM samples showed a spectral response from 400 to 800 nm, with a peak at 630 nm. The PBDTT-DPP:PC71BM structures were sensitive from 400 to 900 nm, exhibiting two maxima at 740 nm and 820 nm. Additionally, structures based on a ternary P3HT:PBDTTDPP:PC71BM blend were developed. These demonstrated a broad spectral response across the 400 to 900 nm range.

Subject of study. This study investigated photosensitive structures with a planar heterojunction based on copper phthalocyanine and 3,4,9,10-perylenetetracarboxylic dianhydride. Aim of study. The aim of this study was to develop organic photosensitive structures based on metal phthalocyanine and a non-fullerene acceptor. Method. Photosensitive structures were fabricated using vacuum thermal deposition. Absorption and photocurrent spectra of these structures were measured. Main results. The optimal parameters for fabricating organic photosensitive structures using a non-fullerene acceptor were determined. The optimal substrate heating temperatures, which influence the quality of the deposited layers, were 60 degrees C and 55 degrees C for copper phthalocyanine and 3,4,9,10-perylenetetracarboxylic dianhydride, respectively. The primary contribution to the photoresponse of the structure was determined to be the charge-carrier generation in copper phthalocyanine. The influence of the evaporated donor mass on the photosensitivity spectra of the structures was also determined. The studied structures exhibited a photoresponse in the energy range of 1.35-2.45 eV. Practical significance. The results of this work can be used in the development of photodetectors based on organic materials for the visible and near-infrared spectral ranges for applications in communication systems, visualization, spectroscopy, medical diagnostics, and other fields. In addition, the developed structures incur lower production costs compared to devices based on conventional inorganic semiconductors. (c) 2025 Optica Publishing Group

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.

Currently, colloidal quantum dots (CQDs) have received considerable attention due to their unique properties, such as the ability to control the band gap in a wide range, the tuning of absorption spectra, the possibility of precipitation from solutions, etc. These properties are especially important for research in the field of detection of electromagnetic radiation in the visible and infrared ranges. The paper presents an overview of photodetectors based on colloidal quantum dots lists the most commonly used materials for creating these devices. Technologies for creating efficient and high-speed photodetectors are described. Particular attention is paid to photodetectors based on metal chalcogenides, which are sensitive in the near infrared range. Advantages and disadvantages of photodetectors based on colloidal quantum dots are described. As well as the results of the introduction of CdSe-based CQDs into organic photosensitive structures of the CuPc/PTCDA type are presented.

The effect of colloidal quantum dots on the optical characteristics of photosensitive layers of the perovskite crystal structure has been investigated. The study used a comparative analysis of photosensitive layers with and without quantum dots. As a result, absorption, transmission and photoluminescence spectra were obtained. It can be concluded that the inclusion of CQD in the composition of perovskite leads to an increase of absorption and a decrease of transmission in the short-wavelength region from the peak of photoluminescence of quantum dots. It can also contribute to the shift of perovskite photoluminescence peak to the long-wavelength region.

The optical properties of bromine-doped organic-inorganic perovskite thin layers were investigated. Replacing iodine, which is component of perovskites, with bromine improves film properties due to the formation of a more stable crystal structure. In this study, perovskite films MAPbI2Br, MAPbBr3, FAPbI 3-x Br x , FA 0,85 Cs 0,15 Pb(I 0,85 Br 0,15 ) 3 and Cs0,05(FA x MA 1-x ) 0,95 PbI y Br 3-y , were obtained by spin-coating method. To determine the optimal technological parameters, such as the spin-coating speed, annealing time and temperature, we studied the photoluminescence and absorbance spectra of the created films. It was found that the use of an antisolvent leads to an increase in the photoluminescence intensity, which can be attributed to the formation of a better-quality film with fewer defects.

LED radiation with the correct spectral composition can significantly increase the nutritional value of cultivated crops. At the same time, it should be borne in mind that each plant needs a certain spectrum at each stage of growth. In the present work, the influence of far-wave and short-wave LED radiation on the growth of lactuca sativa I was studied. The Photosynthetic photon flux density (PPFD) values were obtained depending on the pump current and the distance from the source to the radiation receiver. The following ratios of light fluxes of the short-wave and long-wave ranges of the spectrum were used: 100 % /0 % , 75 % /25 % , 50 % /50 % , 25 % /75 % and 0 % /100 % . We defined optimal ratios of light fluxes to increase the rate of appearance of cotyledons: for 200 µmol.m −2 .s −1 by samples under illumination modes of 75% red / 25% blue light and 100% red; for 300 µmol.m −2 .s −1 at 25% red/ 75% blue and 100% red. It has been proven that with an increase in the proportion of the red range of the spectrum, the rate of appearance of the first and second characteristic lactuca sativa l leaves increase. The highest net weight yield and leaf area were achieved with 75% red light and 25% blue light.

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.

The paper considers the process of creating a programmable LED lamp, which contains LEDs in the UV, visible and far red spectral ranges for the crops germination. The following functions have been added to the software for controlling the lamp: lamp on and off time (time range of operation); number of working days; settings for the internal real-time clock; changing the intensity of the each LED circuit luminescence by day; lamp on/off function from the menu. The device has also been added the ability to record lighting programs.

The simulation of a greenhouse for the Arctic regions was carried out, which operates autonomously using solar and wind energy, as well as adapted to low temperatures and capable of producing plant products directly on the territory of the Russia Federation Arctic zone. To develop the project, a comprehensive work was carried out to study all aspects of the greenhouse installation and all the systems necessary for its successful operation, namely: the design of the greenhouse container, the design of the growing rack, the heating system, the irrigation system, the lighting system, the humidification system, the cooling systems, power supply.

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.

The paper considers the process of creating an automated hydroponic installation with LED lighting in the UV and visible ranges of the spectrum for the germination of agricultural crops. The system implements remote monitoring of microclimate parameters, which include humidity and air temperature, oxygen and carbon dioxide indicators, lighting for effective plant growth. Maintenance of the required operating modes of the installation is automated.

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.

This paper presents a 2D model of a high-power semiconductor laser, which takes into account carrier transport across the layers of its heterostructure and longitudinal spatial hole burning (LSHB), an effect related to the nonuniform gain distribution along the cavity axis. We show that the use of the 2D model which takes into account carrier transport across the layers of the heterostructure allows an appreciable contribution of LSHB to saturation of light – current characteristics to be demonstrated. The LSHB effect, causing a decrease in the output optical power of semiconductor lasers, is shown to be stronger at high drive currents and low output mirror reflectivities. In the case of high drive currents, the LSHB-induced drop in power is related to the faster growth of internal optical and recombination losses because of the nonuniform current density distribution along the cavity axis, such that the highest current density can be almost twice the lowest one. LSHB is shown to increase the power stored in a Fabry – Perot cavity, which is an additional mechanism reducing the output optical power.

It is known that semiconductor light-emitting diodes (LEDs) based on various solid solutions are used as effective sources of radiation for supplemental illumination of plants. The study of the influence of LED radiation based on AlGaInP (660 nm and 730 nm) and full-spectrum (400 - 800 nm) phosphor "phyto-LEDs" (emission maxima at 440 nm and 660 nm) on the growth and development of tomato sprouts in the germination stage was made. The spectral and energy characteristics were measured and the density of the photosynthetic photon flux was calculated for each type of LED. Studies showed that irradiation of seeds with light with a maximum spectral luminescence characteristic of 660 nm increased germination by 4% compared to control samples and by 29% compared to samples germinated under phyto-LEDs. Irradiation with a combination of red (660 nm) and far red (730 nm) light in a ratio of light fluxes of 1: 1 decreased the results of germination of tomato seeds by 41% compared to the control batch.