Thin Cells Research Articles

Malic acid inhibits accumulation of cadmium, lead, nickel and chromium by down-regulation of OsCESA and up-regulation of OsGLR3 in rice plant

Malic acid (MA) plays an important role in plant tolerance to toxic metals, but its effect in restricting the transport of harmful metals remains unclear. In this study, japonica rice NPB and its fragile-culm mutant fc8 with low cellulose and thin cell wall were used to investigate the influence of MA on the accumulation of 4 toxic elements (Cd, Pb, Ni, and Cr) and 8 essential elements (K, Mg, Ca, Fe, Mn, Zn, Cu and Mo) in rice. The results showed that fc8 accumulated less toxic elements but more Ca and glutamate in grains and vegetative organs than NPB. After foliar application with MA at rice anthesis stage, the content of Cd, Pb, Ni significantly decreased by 27.9–41.0%, while those of Ca and glutamate significantly increased in both NPB and fc8. Therefore, the ratios between Cd and Ca in grains of NPB (3.4‰) and fc8 (1.5‰) were greatly higher than that in grains of NPB + MA (1.1‰) and fc8+MA (0.8‰) treatments. Meanwhile, the expression of OsCEAS4,7,8,9 for the cellulose synthesis in secondary cell walls were down-regulated and cellulose content in vegetative organs of NPB and fc8 decreased by 16.7–21.1%. However, MA application significantly up-regulated the expression of GLR genes (OsGLR3.1-3.5) and raised the activity of glutamic-oxalacetic transaminease for glutamate synthesis in NPB and fc8. These results indicate that hazard risks of toxic elements in foods can be efficiently reduced through regulating cellulose biosynthesis and GLR channels in plant by combining genetic modification in vivo and malic acid application in vitro.

The Computed Sinusoid

Hepatic sinusoids are lined with thin endothelial cells with transcellular pores, termed fenestrations. These fenestrations are open channels that connect the sinusoidal lumen to the underlying Space of Disse (SoD) and the hepatocytes of the liver parenchyma. Fenestrations range from 0.05 to 0.35 µm in diameter and cover 5–15% of the sinusoidal endothelial surface area, depending on their location along the sinusoids. The direct measurement of hemodynamic parameters, such as pressure and flow velocity, remains challenging within the narrow sinusoids. Such knowledge would increase our understanding of the physiology of the hepatic niche and possible implications in aging or diseases in which fenestrations are reduced or lost. Few simulations of liver blood flow focus on the level of the individual sinusoid, and fewer still include the transcellular pores (fenestrations) of the sinusoidal endothelium. Furthermore, none have included (i) a porosity gradient along the sinusoid wall, modeled using through-all pores rather than a porous medium, (ii) the presence of the SoD, or (iii) lymphatic drainage. Herein, computed fluid dynamics (CFD) simulations were performed using a numerical model with relevant anatomical characteristics (length, diameter, porosity, inlet/outlet pressure, and lymphatic outflow from the portal region of the SoD). The greatest contribution to luminal velocity magnitude and pressure was the overall shape of the vessel. Divergent-radius models yielded velocity magnitudes 1.5–2 times higher than constant-radius models, and pressures were 5–8% lower in the divergent-radius models compared to the constant-radius models. Porosity only modestly contributed to luminal pressure. The luminal velocity magnitude was largely unaffected by the presence or absence of lymphatic drainage. Velocity magnitudes through fenestrations were lower in higher-porosity models (20%) vs. lower-porosity models (5%) across all models (0.4–0.55-fold lower). Velocity magnitudes through the space of Disse were increased 3–4 times via the addition of lymphatic drainage to the models, while pressures were decreased by 6–12%. The flow velocity in the SoD was modified via differences in porosity, while the flow velocity in the lumens of the sinusoids was largely unaffected. The overall shape of the vessel is the single most important factor in the pressure flow behavior of the sinusoidal lumen. The flow rate over hepatocytes and the SoD is modestly affected by the distribution of porosity along the sinusoid and greatly affected by the lymphatic drainage, parameters that would be of interest for modeling the exchange of blood with the hepatic parenchyma.

Callus Induction of Dendrobium discolor Through The Thin Cell Layer (TCL) Technique Added with 2,4-Dichlorophenoxyaceticacid

Thin Cell Layer (TCL) is a plant propagation technique using thin explants (1-2 mm) through tissue culture. Callus induction is a crucial step in establishing plant regeneration. The type and concentration of growth regulators influence callus formation. 2.4 D is a growth regulator that is commonly used for callus induction in various plants. The research aims to determine the effectiveness of thin explants and 2,4-D in inducing Dendrobium discolor callus. The method used a Completely Randomized Design (CRD) with four treatments (1, 2, 3, and 4 mg/L). Adding 1, 2, and 3 mg/L 2,4-D can induce 100% calluses through the TCL explant. The callus has a friable to compact texture. The result showed that 2 mg/L 2,4-D was the best concentration for callus induction of D. discolor through TCL technique, indicating the greenish color, friable texture, and meristematic tissue.

Simultaneous inclusion of quantum dots in multi-functional layers of thin film organic solar cells

The role of quantum dot (QD) decoration in the hole transport buffer layer and the photoactive medium on the photovoltaic parameters of thin film organic solar cells (TFOSCs) was investigated. A cadmium–tellurium-based QD was synthesized successfully and embedded in two of the functional layers of a TFOSC to improve its overall power conversion efficiency. The experimentally determined optimum concentration of the QD was maintained in the interfacial layer to investigate the effect of QD concentration in the active layer. The observed increased short-circuit current density (Jsc) and open circuit voltage (Voc) are attributable to the enhanced energy level tuning, broadened optical absorption, and charge transport process facilitated by the integration of QDs inside the media. Moreover, an improved device efficiency was obtained when the solvent additive was introduced into the bulk heterojunction photoactive layer films to facilitate QD dispersion and increase the interpenetrating network of the active layer blend that reduces the occurrence of trap sites, which, in turn, limits the Auger recombination rates. The QD-doped TFOSCs catalyzed with solvent additives displayed an enhanced overall photovoltaic parameter, which is quite appreciable in comparison with that of the pristine devices.

Realization of performance enhancement of thin film silicon solar cells by applying ITO/AZO bilayer TCO films as front electrode

Realization of performance enhancement of thin film silicon solar cells by applying ITO/AZO bilayer TCO films as front electrode

A modified drop-casting technique for efficient lead-free, environment-friendly thin film CsBi3I10 perovskite solar cells

The efficiency of lead-based perovskite solar cell deteriorates due to their instability and toxicity which inhibits their commercial application. Both of these issues are resolved by substituting Bismuth in place of lead. In order to create environmentally friendly perovskite solar cells (PSCs), bismuth-based halide perovskite (CsBi3I10) is a promising absorber material. Bismuth-based CsBi3I10 perovskite films were fabricated using a modified drop-casting process at room temperature. With this technique, you can get a film with desirable characteristics including a smooth, uniform surface and no pinholes. A comprehensive analysis is carried out in this research article as a result of the fact that thermal annealing is the first step in the process of transforming the deposited solution into the perovskite material. Band gap tuning is achieved with the use of this heat treatment. As film that has been post-annealed at the low temperature of 60 °C is not only tuned in terms of conductivity with a low band gap of 1.78 eV, but it also has improved absorption. In contrast, hexagonal particles with a low absorbance and a greater band gap of 2.08 eV develop at higher post-annealing temperatures. Band gap is greater (2.21 eV) and nonhomogeneous layered structure is formed in the film that does not undergo any post annealing treatment. The effects of post-annealing temperature on morphological, structural, and optical properties are explored and connected with photovoltaic application requirements. Finally, the photovoltaic performance of PSCs based on CsBi3I10 without hole transport layer (HTL) is investigated quantitatively in this study.

Effect of spermidine, glutamine, and proline on somatic embryogenesis and silver nanoparticles supplied culture improved rhizome formation of Panax vietnamensis var. langbianensis

Lang Bian ginseng (Panax vietnamensis var. langbianensis) is a rare and traditional herbal medicine with many pharmacological activities. It was first discovered by Duy et al. (2016) in Lam Dong province, Vietnam. Until now, there has been only one publication on Lang Bian ginseng micropropagation via somatic embryogenesis (Anh et al., 2022). However, this study still had limitations, including the small number of somatic embryos and the time-consuming. This study investigated the effect of spermidine, glutamine, and proline on the enhancement of somatic embryogenesis (SE) of Lang Bian ginseng using thin cell layer culture technology. The results showed that the optimal SE rate and the number of somatic embryos per explant were achieved on MS medium supplemented with 0.01 mM spermidine in leaf explants (93.32 % and 54.20 embryos, respectively) and petiole explants (96.66 % and 68.80 embryos, respectively) and higher compared to these in other treatments, including control, glutamine, and proline treatments. Besides, adding 0.01 mM spermidine to the culture medium also improved the quality of somatic embryos, mainly cotyledonary stage, through an enhanced synthesis of antioxidant enzymes [catalase (CAT) and superoxide dismutase (SOD), and ascorbate peroxidase (APX)]. In addition, the fluctuations of endogenous hormones during initiation and maturation of SE derived from 0.01 mM spermidine treatment were recorded. Endogenous CKs (ZEA, 2iP, KIN, mT), IAA, and GA3 concentrations were the highest during the induction stage in both explants. Meanwhile, the remaining endogenous hormones (MEL, ABA, and SA) exhibited no inevitable fluctuation trends. In addition, IAA was only detected at the induction stage of SE in both explants. Moreover, cotyledonary somatic embryos derived from 0.01 mM spermidine treatment grew well in MS medium supplemented with 1.2 mg/L AgNPs.

Photovoltaic efficiency enhancement via magnetism

The efficiency of photovoltaic cells has long been a subject of intense concern and research. Diverse photovoltaic cell types have been developed, including crystalline silicon cells (achieving up to 27.6% efficiency), multijunction cells (reaching up to 47.4% efficiency), thin film cells (attaining up to 23.6% efficiency), and emerging photovoltaic cells (exhibiting up to 33.7% efficiency). Despite advancements, achieving high efficiency on an industrial scale remains a significant challenge due to factors like charge carrier recombination rate, defects, temperature’s influence, etc. Numerous approaches have been explored to address these challenges, encompassing strategies such as incorporation of nanoparticle within the active layer, studying transport properties and defects using ion beams, utilizing magnetite materials, and leveraging the application of magnetic fields. The influence of a magnetic field can amplify the generation of charge transfer states exhibiting triplet characteristics, increasing the charge separation time. However, magnetic fields introduce spin-based effects, enabling the investigation of interactions between electron spins and magnetic fields through state-of-an-art synchrotron radiation techniques like XMCD. Several innovative cell configurations have reported substantial efficiency enhancements under the influence of magnetic fields. Examples include TiO2-BiFeO3 dye-sensitized cells, polymer-based cells with Fe3O4@PANI additives integrated into TiO2-based dye-sensitized cells, and the incorporation of Fe-doped SnO2 within the active layer of heterojunction organic solar cells. In this perspective review, the profound impact of magnetism on enhancing efficiency in photovoltaic cells has been analysed and the utilization of advanced X-ray absorption spectroscopic techniques to probe and comprehend these intricate effects.

Extraction and Characterization of Novel Ligno-Cellulosic Fiber from Wrightia tinctoria and Cebia pentandra Plant for Textile and Polymer Composite Applications

Natural fibers derived from cellulose and ligno-celluloses materials have many advantages, such as being renewable, low density, inexhaustible, and cheap rather than synthetic fibers. Researchers and scientists are searching for a new fiber source that can be processed environmentally sustainable. The aim is to produce an organic and Eco-friendly product. The present investigation aims to extract and characterize ligno-cellulosic fiber from the seedpod of Wrightia tinctoria (WT) and Cebia pentandra (CP) plants. The extraction of WT fibers (WTFs) and CP fibers (CPFs) was carried out using the hand-stripping method. The structural and functional Characterization of WTFs and CPFs were determined using Scanning Electron Microscope (SEM), Fourier Transform Infrared (FT-IR) spectroscopy, Chemical analysis, X-ray diffraction studies (XRD), and the thermal behavior of fibers determined by using Thermo Gravimetric Analysis (TGA). The results indicated that WTFs composed of 75% cellulose, 14% lignin, and 0.55% wax content were, as the CPFs were composed of 38% cellulose, 15% lignin, and wax content of 2.34%. The SEM micrograph confirms that both fibers were hollow structures with thin cell walls and luminous because of the wax content presence on the surface of the fiber. The crystallinity percentage of WTFs and CPFs was calculated from XRD studies and is valued at 62% and 52%. Thermo gravimetric analysis revealed that WTFs and CPFs were thermally stable up to 460°C and 350°C. The above characterization results confirm that WTFs and CPFs have a wide scope in textile and polymer composite applications.

Thin film Si solar cell and solid oxide fuel cell technologies for a low cost, environmentally friendly and sustainable source of energy

Thin-film solar cell technology based on hydrogenated amorphous silicon has matured over the last two decades and is capable to deliver commercial modules with almost 10 % stabilized efficiency. Moreover attention on hydrogen fuel cells is increasing as the range of potential commercial applications expands, with more than 3800 fuel cell systems being installed and operated worldwide. These systems attain high theoretical efficiencies in the range of 43.7-70.4 %, with an additional 20% as heat recovery, and operating at carbon-free conditions between 50 °C and 900 °C. In this paper the status of thin-film silicon solar cell technology is reviewed by comparing it to other major solar cell technologies. A discussion is also made upon the benefits obtained from the few potential applications, as long-term potential actions for sustainable development, and the future of Solid Oxide Fuel Cells (SOFCs). Applications of thin-film silicon modules and SOFCs are presented. EPIA (European Photovoltaic Industry Association) estimates that half of the growth in the next two years will come from thin-film technology.

A CTL-free homo-heterojunction antimony chalcogenide solar cell: Theoretical study

Exploring antimony chalcogenide as photovoltaic (PV) absorber material for solar cell is an appealing strategy. However, the conversion efficiency (η) of antimony chalcogenide solar cells including antimony selenide (Sb2Se3), antimony sulfide (Sb2S3) and antimony sulfide–selenide (Sb2(S,Se)3) lag far behind their Shockley−Queisser limit efficiency. Generally, the device PV performance of thin film heterojunction solar cells is mainly affected by the material properties of each functional layer, as well as the device architecture and heterointerface characteristics. Herein, a novel homo-heterojunction antimony chalcogenide solar cell without any carrier transport layer (CTL) consisting of FTO/(n)Sb2Se3/(p)Sb2Se3/(p)Sb2S3/Metal has been proposed. The influence of thickness, doping concentration and bulk defect density of the functional layer materials, the interface defect density at (p)Sb2Se3/(p)Sb2S3 heterointerfaces, and back contact metal work function on device PV performance have been theoretically analyzed utilized wxAMPS software. After optimization, the proposed solar cell has an open-circuit voltage (Voc) of 0.885 V, a short-circuit current density (Jsc) of 36.14 mAcm−2, a filling factor (FF) of 84.30 %, and a η of 26.97 %. These results indicate that the novel homo-heterojunction antimony chalcogenide solar cell without any CTL have the potential to become a high-efficiency PV device.

Pharmacognostic Evaluation of Simarouba glauca DC Bark

Simarouba glauca DC also known as ‘Dysentery Bark’ is an important ethnomedicinal plant native to Tropical America. Later introduced India as “Lakshmi-Taru.” Bark is a potent anti-microbial, anti-diabetic, anti-cancer, and hemolytic drug. This study presents a pharmacognostic evaluation of Simarouba glauca DC bark, mainly shedding light on its macroscopic and microscopic characteristics. Identification, authentication, macroscopic observation, and TLS, RLS and Powder microscopical examinations have been carried out.
 The macroscopic examination of the bark revealed distinctive features, including a rough, fissured surface, and a yellowish-brown colour. Microscopic analysis showcased the presence of a thick periderm with small flakes raised above the periderm surface. The outer part of phellem is crushed and the inner portion is modified into a thick cylinder of sclereids. The Phelloderm becomes thick walled and dark coloured and stores calcium oxalate crystals. Large prismatic calcium oxalate crystals located in uniseriate vertical row within thin parenchyma cells. TLS revealed that the phloem fibers in dense compact bundles. The fibers being highly thick walled and lignified with narrow cell lumen. The rays are 250-280 µm in height and 40-60µm. RLS showed the rays are rentered heterocellular. Parenchyma cells and fibers are vertical position at right angles to the rays. Bark powder microscopy exhibited the presence of narrow and wide fibers, fiber-sclereids, long sieve elements, thick brachy sclereids, and large quantity of quadrangular, rectangular, and polygonal Calcium oxalate crystals. These observations provide valuable diagnostic tools for the authentication and quality control of S. glauca DC bark.
 The pharmacognostic characterization presented in this study serves as a foundation for further research and development of S. glauca DC bark-based herbal medicines and pharmaceutical formulations. The insights provided in this article contribute to the understanding and utilization of this valuable botanical resource, fostering a bridge between traditional knowledge and contemporary scientific approaches in pharmacognosy.

Semiconductor quantum dots as a mechanism to enhance charge transfer processes in polymer solar cells

The light trapping capability of thin film polymer solar absorber, composed of poly (3-hexylthiophene) and [6,6]–phenyl C61- butyric acid methyl ester (P3HT:PC60BM) blend, is improved using ZnS semiconductor quantum dots (QD) as third donor-acceptor (D:A) component. The inherent characteristics of the microwave-assisted synthesized ZnS QD, such as quantum size effect, and multiple exciton generation were leveraged in harvesting high energy photons, which resulted in a better exciton generation, dissociation, and effective charge transport in the polymer medium. The synthesized QD exhibited good phase purity, effective kinetic enhancement, and control of the aggregation process. Hence, the impact of ZnS QD on the performance of thin film polymer solar cells (TFPSC) is evident by a remarkable improvement in the measured photovoltaic parameters. Nonetheless, it is observed that the device performances are generally dependent on the concentration of the QD in the absorber layer. Consequently, the power conversion efficiency has increased by 58% at 3% concentration of QDs by weight. This is an interesting development of TFPSC fabricated under an ambient environment.

Prediction of band gap and optimum electrical parameters of a thin homojunction perovskite solar cell based on FA1−xCsxSnyPb1−yI3 through a combination of SCAPS-1D and machine learning based modelling

This paper presents a machine learning (ML) model developed to predict the band gap and optimum electrical parameters of a thin homojunction perovskite solar cell (PSC) based on FA1−xCsxSnyPb1−yI3. For different cesium (x) and tin (y) compositions, band gaps are tabulated, and electrical parameters such as open circuit voltage, short circuit current, and power conversion efficiency are generated in standard test condition (STC) using the SCAPS-1D platform. The data obtained are used to build two sub-models wherein first Model 1 uses the composition to predict the band gap and second Model 2 uses the predicted band gap to predict the electrical parameters using a polynomial regression algorithm. The sub-models are then connected in series. Train and test scores, correlation (r), and root mean square error (RMSE) are calculated to investigate the accuracy of the models while the cross-validation score checks the stability and the overfitting of the models. The final, best performance model’s metrics–R2, r, and RMSE, are 0.99, 0.99, and 0.09 respectively for Model 1 and 0.97, 0.99, and 0.28 for Model 2. These are achieved for a fourth order polynomial. In addition, we realize that the homojunction PSC based on FACsSnPbI3 offers a high efficiency of 17.17% for a band gap of around 1.44 eV. We also reveal that the presence of tin induces lattice contraction, affects the stability, and changes the configuration of the crystal structure from cubic to octahedral tilting when tin composition increases.

Enhanced ZnO-based ETL and nanostructured interface modification for improved perovskite solar cells efficiency

Compared to standard silicon solar cells and other thin film cells, perovskite solar cells (PSCs) can achieve high power conversion efficiency and reduce the production costs. ZnO-based ETL in perovskite solar cells provides a lot of benefits, such as low processing temperature and high mobility. However, the reported instability of perovskite layers placed atop ZnO, resulting in poor device performance, has prevented it from being widely used in perovskite solar cells, though. In this work, an innovative way of insuring device performance and longer-term stability is proposed via the incorporation of a novel efficient process. Herein, a V-doped ZnO/Y-doped TiO2 electron transport bilayer was developed to combine the benefits of strong electron extraction and minimal interfacial recombination. This combined approach of engineering both the improved performance of VZnO as ETL and YTiO2 flower like structures at the interface ETL/Perovskite results in large improvements in the performance of the PSC. V-doped ZnO (VZnO) was introduced into the PSC structure as an ETL, due to its excellent electrical and optical properties, to improve electron extraction efficiency, with a doping amount of 4 at.% of vanadium. The latter has been optimized in our previous study. On the other hand, extrinsically doping TiO2 with an amount of 5 at.% of Yttrium (YTiO2) was utilized to enhance its physicochemical properties. The PSC based on VZnO/YTiO2 bilayer ETL possess the best PCE of 15.1%, compared to 9.4% in the pristine ZnO-based ETL solar cell, with the open-circuit voltage (Voc) of 923 mV, short-circuit photocurrent density (Jsc) of 22 mA cm−2, and fill factor (FF) of 74%. Obtained improvements are ascribed to the suppressed charge recombination via the incorporation of YTiO2 flower-like nanostructures at the interface VZnO/perovskite and the enhanced electron transporting in the resulting ETL bilayer structure.

Oscillations and bistability of complex electrochemical reactions in 3D printed microfluidic devices

We investigate the kinetic features of complex charge transfer chemical reactions using a microelectrode integrated in a flow cell made with 3D printing technology. Thin layer electrochemical cells with 350 μm (height) × 1000 μm (width) channels were designed. Ferrocyanide oxidation on a 100 μm diameter Pt electrode using the printed cell showed mass transfer limiting current at large overpotentials. The variation of the limiting current with the flow rate (1 μL/min ≤ Q ≤ 100 μL/min) was interpreted with the superposition of a constant current due to radial diffusion and a Levich-type square-root relationship, indicating a mixed radial diffusion/thin layer mass transport condition. These findings were further supported by numerical simulation of a diffusion-convection equation in the flow channel. Experiments with copper electrodissolution in phosphoric acid electrolyte reproduced oscillatory behavior that was previously seen in macrocells and polydimethylsiloxane (PDMS) microchips. The 3D printed cell can accommodate multiple electrodes – to demonstrate this application we showed that the current oscillations with copper electrodissolution can exhibit frequency synhcronization with a dual electrode configuration. Finally, hydrogen oxidation on a Pt wire in the presence of Cu2+ and Cl− inhibitors displayed bistability at relatively large external resistance and oscillations at high volumetric flow rates. The results show that the 3D printed thin layer design is an alternative to studying nonlinear phenomena in electrochemical cells with distinct advantages to the traditional approaches of using macrocells and PDMS microchip flow cells.

Performance evaluation of ZnSnN2 solar cells with Si back surface field using SCAPS-1D: A theoretical study

The earth-abundant semiconductor zinc tin nitride (ZnSnN2) has garnered significant attention as a prospective material in photovoltaic and lighting applications, primarily due to its tunable narrow bandgap and high absorption coefficient. This study focuses on a numerical investigation of ZnSnN2 solar cell structures using the SCAPS 1-D software. The objective is to analyze the influence of various physical and geometrical parameters on solar cell performance. These parameters include the thicknesses of the ZnO window layer, CdS buffer layer, ZnSnN2 absorber layer, and Si back surface field layer (BSF), as well as operating temperature, series and shunt resistances (RS and Rsh), absorber layer defect density, interface defects, and the generation-recombination profile of the n-ZnO:Al/n-CdS/p-ZnSnN2/p-Si/Mo structure. We have evaluated the capabilities of this novel material absorber by investigating its performance across a range of thicknesses. We have started with ultrathin absorber thicknesses and gradually increased them to thicker levels to determine the optimal thickness for achieving high efficiency. Under optimal conditions, a thin solar cell with a thickness (wp) of 1 μm achieved an efficiency (η) of 23.9%. In a practical solar cell operating at room temperature, optimal parameters were observed with a thicker absorber layer (wp = 8 μm) and a BSF width of 0.3 μm. The cell exhibited resistances of Rsh = 106 Ω cm2 and Rs = 1 Ω cm2, along with a low defect density (Nt = 1010 cm−3) in the ZnSnN2 semiconductor. These factors combined to yield an impressive efficiency of 29.5%. Numerous studies on emerging ternary nitride semiconductors (Zn-IV-N2) have highlighted ZnSnN2 as a promising material for thin-film photovoltaics. This compound is appealing due to its abundance, non-toxicity, and cost-effectiveness. Unlike conventional solar cells that depend on rare, toxic, and costly elements, these components are still essential for today's solar cell technology.

A Review on the Fundamental Properties of Sb2Se3-Based Thin Film Solar Cells

There has been a recent surge in interest toward thin film-based solar cells, specifically new absorber materials composed by Earth-abundant and non-toxic elements. Among these materials, antimony selenide (Sb2Se3) is a good candidate due to its peculiar properties, such as an appropriate bandgap that promises a theoretical maximum power conversion efficiency of 33% and an absorption coefficient of around 105 cm−1, enabling its use as a thin film absorber layer. However, charge carrier transport has been revealed to be problematic due to its cumbersome structure and the lack of a doping strategy. In this work, we aim to provide a clear picture of the state-of-the-art regarding research on Sb2Se3-based solar cells and its prospects, from the successful achievements to the challenges that are still to be overcome. We also report on the key parameters of antimony selenide with a close focus on the different characteristics associated with films grown from different techniques.

Creation of a Photobioreactor for the Effective Growth of Chlorella and Study of the Effect of the Spectral Composition of Light on Its Biomass

Chlorella is a green eukaryotic microalga (Chlorella vulgaris). The microscopic cell is spherical, 2–10 μm in diameter. This microalga is one of the most important and promising for biomass production. Chlorella is cultivated in ponds or bioreactors with specified parameters that create favorable conditions for the growth of chlorella biomass. Each set of conditions creates the opportunities for changing the growth rate and output of individual products. Two strains of chlorella were the object of the study: 1 – chlorella with a thin cell wall (Chlorella vulgaris VKPM Al-24); 2 – chlorella with a thick cell wall (Chlorella vulgaris Beijer). The culture of chlorella was cultivated on modified Tamiya nutrient medium, at 24°C and 24-hour illumination. It was cultivated for 5 days in 1000 ml flasks, in opaque grow boxes with different lighting regimes. The control variant was grown in a light room with white fluorescent lamps with an intensity of 150 μmol/m2 s, and the culture was also grown in the dark. Laboratory experiments studying the effect of spectral composition of light on growth of two strains of chlorella culture allowed identifying some regularities: 1 – the largest increase in biomass is observed when using white fluorescent lamps (T = 2700K); 2 – in the case of using FR>R or FR=R, their inhibitory effect on the growth of the studied strains of chlorella was observed. In addition, similar results were obtained when determining the optical density of the cultures, suggesting that the chlorella strains studied are similarly responsive to the action of different spectral compositions of light. Analyzing the absorption spectrum, it should be noted that it has a continuous character. It has been experimentally established that the first maximum is located in the red region (660 to 690 nm) and the second in the blue region (430 to 450 nm). The minimum absorption is observed in the green light region (500 to 610 nm).

A liquid crystal smart window for energy saving and harvesting

Energy conservation, particularly in buildings, has become a critical focus area. Among the various components of a building, windows play a significant role in the exchange of heat and light. Electrochromic systems, known for their ability to switch between transparent and opaque states with the aid of external energy, have served as the basis for conventional smart windows. This research introduces a novel approach to smart window technology by incorporating a luminescent solar concentrator (LSC) that incorporates thin photovoltaic cells at the window's edges, coupled with a thermally and optically adjustable liquid crystal cell. The device intelligently transitions between an energy-saving, opaque mode (day mode) and a transparent, idle mode (night mode), based on ambient temperature and incident light levels. Through this innovative design, the proposed smart window offers enhanced energy efficiency and harvesting capabilities, promising significant benefits for sustainable building practices.