Sodium Selenosulfate Research Articles

Innovative In Situ Passivation Strategy for High-Efficiency Sb2(S,Se)3 Solar Cells.

An effective defect passivation strategy is crucial for enhancing the performance of antimony selenosulfide (Sb2(S,Se)3) solar cells, as it significantly influences charge transport and extraction efficiency. Herein, a convenient and novel in situ passivation (ISP) technique is successfully introduced to enhance the performance of Sb2(S,Se)3 solar cells, achieving a champion efficiency of 10.81%, which is among the highest recorded for Sb2(S,Se)3 solar cells to date. The first principles calculations and the experimental data reveal that incorporating sodium selenosulfate in the ISP strategy effectively functions as an in situ selenization, effectively passivating deep-level cation antisite SbSe defect within the Sb2(S,Se)3 films and significantly suppressing non-radiative recombination in the devices. Space-charge-limited current (SCLC), photoluminescence (PL), and transient absorption spectroscopy (TAS) measurements verify the high quality of the passivated films, showing fewer traps and defects. Moreover, the ISP strategy improved the overall quality of the Sb2(S,Se)3 films, and fine-tuned the energy levels, thereby facilitating enhanced carrier transport. This study thus provides a straightforward and effective method for passivating deep-level defects in Sb2(S,Se)3 solar cells.

Mathematical approaches to a method of semiconductor materials films synthesis type AiiBvi for photosensitive structures used in alternative energy

The scientific direction of the synthesis of CdS and CdSe thin films by the method of chemical surface deposition (CSD) using aqueous solutions of cadmium-containing salts: chloride, nitrate, sulfate, acetate, iodide has been developed. A mathematical model of the CSD process of CdS and CdSe thin films was developed to improve the efficiency of experiments and reduce costs. The model makes it possible to determine the concentration of reagents, the duration, and the CSD temperature, which are necessary to obtain films of a specified thickness. The optimization of chemical deposition parameters of film-type semiconductor materials has been carried out. Based on the mathematical model, the optimal synthesis conditions were the next: concentration of cadmium-source salt - 0.01 mol/L, chalcogenizer - 1.0 mol/L or 0.1 mol/L in the chase of thiourea or sodium selenosulfate, respectively; temperature - 70?C and duration of 3 min. The mathematical dependence of the experimental studies results of the metal ions content in thin-film solar cells for the effective direct conversion of solar radiation into electrical energy taking into account errors was proposed.

Nanoarchitectonics of self-grown copper selenide on copper for solid-state asymmetric supercapacitor

The ability of anode materials to store energy depends on their rate capability, which is limited by the slow reaction kinetics at the interface between the electrode and the electrolyte. Here, a self-supported Cu3Se2@Cu electrode was developed using a facile self-growth technique at various immersion times in sodium selenosulfate solution. The transformation of Cu to Cu(OH)2 and further into Cu3Se2 with alteration of surface morphology depends critically on the immersion time. A film with a nanosheet-type morphology prepared with 2 h immersion time achieved a specific capacitance of 928 F cm−2 at a scan rate of 2 mV s−1. Due to the open cage-like structure and nanosheet-type morphology, the self-grown electrodes had excellent electrochemical stability of 87 % over 5000 charge-discharge cycles. Having excellent high electrochemical activity, self-grown Cu3Se2 is ideal for the fabrication of supercapacitor devices and combined with activated carbon to assemble an asymmetric supercapacitor (ASC). The ASC provides an energy density of 30.8 Wh kg−1 at 461 W kg−1 with a retention of 98 % capacitance up to 5000 galvanostatic charge-discharge cycles. This study offers insight into the conversion of Cu substrate to Cu3Se2 for supercapacitor applications possessing high rate capacity and is expected to facilitate the development of self-grown selenide-based electrodes from the metal substrate providing new insights.

Shortening the sulfur cell cycle by a green approach for bio-production of extracellular metalloid-sulfide nanoparticles

In the present study, a new approach was introduced regarding the extracellular synthesis of selenium sulfide micro/nano-particles using Saccharomyces cerevisiae in different ammonium sulfate supplementation and in the presence of sodium selenosulfate precursors (S1) and a blend of selenous acid and sodium sulfite (S2). In S1, only cell supernatant exposed to ammonium sulfate was able to reduce sodium selenosulfate. Whereas, in S2, cell supernatant in both pre-conditions of with or without ammonium sulfate (S2 + or S2−) were able to reduce selenous acid and sodium sulfite. Electron microscopy, also indicated that selenium sulfide NPs were successfully synthesized with average size of 288 and 332 nm for S2 + and S2− in SEM and 268 and 305 nm in TEM. Additionally, elemental mapping by energy-dispersive x-ray analysis confirmed the presence of sulfur/selenium elements in the particles in a proportion of 24.50 and 23.31 for S2− and S2 + , respectively. The mass spectrometry indicated the probability of Se2S2, SeS1.1, Se2, Se, SeS5, SeS3, Se3S5/Se5, Se3/SeS5, Se6, Se4/SeS7, Se2.57S5.43/Se2S2 and Se4S/Se2S6 molecules for S2 + and of Se, Se2, Se3S5/Se5, Se6 and Se4 species for S2−. In FTIR spectra, primary (i.e. 1090–1020 and 1650–1580 cm−1) and secondary (1580–1490 cm−1) amine bands duly confirmed the protein corona around the NPs.

Studies on optical and electrical properties of PVA capped nanocrystalline CdSe thin film prepared by chemical bath deposition method

PVA-capped nanocrystalline CdSe thin films are deposited on chemically clean glass substrates by chemical bath deposition technique using Cadmium acetate [Cd(CH3COO)2.3H2O and Sodium Selenosulfate (Na2SeSO3) as Cd2+ and Se2- ions sources respectively. Polyvinyl Alcohol (PVA) is act as a capping agent. Films of five different molarities (0.1 M–0.50M) of same pH value 8 were prepared at room temperature 298 K. The characteristics of the prepared CdSe thin films are investigated in detail by measuring their optical and electrical properties. The band gap energy of 2.16–2.49 eV was determined from the optical absorption spectra. The optical band gap decrease with increase in molarities. The electrical conductivity measured using two co-planar Aluminium electrodes are found to increase with increase in temperature showing semiconducting nature of the films. The electrical conductivity at room temperature is found to be of the order of 10-4 Ω-1 cm-1 .

Low-Cost Antimony Selenosulfide with Tunable Bandgap for Highly Efficient Solar Cells.

About 10% efficient antimony selenosulfide (Sb2 (S,Se)3 ) solar cell isrealized by using selenourea as a hydrothermal raw material to prepare absorber layers. However, tailoring the bandgap of hydrothermal-based Sb2 (S,Se)3 film to the ideal bandgap (1.3-1.4eV) using the selenourea for optimal efficiency is still a challenge. Moreover, the expensive selenourea dramatically increases the fabricating cost. Here, a straightforward one-step hydrothermal method is developed to prepare high-quality Sb2 (S,Se)3 films using a novel precursor sodium selenosulfate as the selenium source. By tuning the Se/(Se+S) ratio in the hydrothermal precursor solution, a series of high-quality Sb2 (S,Se)3 films with reduced density of deep defect states and tunable bandgap from 1.31 to 1.71eV is successfully prepared. Consequently, the best efficiency of 10.05% with a high current density of 26.01 mA cm-2 is achieved in 1.35eV Sb2 (S,Se)3 solar cells. Compared with the traditional method using selenourea, the production cost for the Sb2 (S,Se)3 devicesis reduced by over 80%. In addition, the device exhibits outstanding stability, maintaining more than 93% of the initial power conversion efficiency after 30 days of exposure in the atmosphere without encapsulation. The present work definitely paves a facile and effective way to develop low-cost and high-efficiency chalcogenide-based photovoltaic devices.

Electrical Properties of n-CdSe/Si-p Junction Prepared by Chemical Bath Deposition Technique, from Different Weights of Sodium Selenosulfate and Constant Molarity

A pn-junction was successfully fabricated by depositing n-type CdSe thin films on p-type Si as a substrate using chemical bath deposition technique (CBD) at 70oC. Time of deposition was 6 hours and the preparing solution was changed every 2 hours during the deposition. Sodium Selenosulfate (with different weights) is the source of Se-2 ions, cadmium nitrate is the source of Cd+2 ions. The (I-V) characteristics for the n-CdSe/p-Si junction show it behaves as a Zener diode in reverse bias, with Zener resistance (3 and 27×103)W. SEM also shows spherical-shape particles with difference grain size (3.8 and 19.8) nm.

Tailoring Structural and Optical Properties of Cu Doped Chemically Deposited ZnSe Nanostructured Thin Films

Chemical bath deposition has been used for depositing undoped and copper doped ZnSe thin films at 343 K temperature. Growth of the thin film requires zinc sulphate cation and sodium selenosulphate anion. The preparative parameters are optimized with an aim to obtain high quality thin films. Three different concentrations of Cu source are used. XRD pattern indicates the incorporation of copper in to polycrystalline cubic ZnSe in doped thin films and is confirmed by EDAX spectrum. SEM micrographs indicate that ZnSe dispersion in the films is homogeneous. UV–visible transmission spectra of the thin films have put into evidence that the dispersion of ZnSe nanocrystals in the thin film is improved their optical transmission. Room temperature PL spectra have shown that the addition of Cu into ZnSe enhanced the emission with additional green peak other than blue band edge emission. Electrical conductivity also modified on addition of Copper.

Effect of different concentrations of the precursor on the properties of chemically induced ZnSe thin films

The properties of Zinc Selenide (ZnSe) thin films can be considerably varied by altering the concentration of precursor (Zinc acetate). As a starting material (precursor), zinc acetate and sodium selenosulphate were utilized. For solar applications, ZnSe is one of the most promising materials. The structural, chemical, optical, electrical, and photoelectric characteristics of ZnSe thin films were investigated on non-conducting glass substrates using a chemical bath deposition technique with varying concentration of zinc acetate (precursor) in an alkaline solution. Concentration affects the crystallinity, surface morphology, light absorption, photocurrent, and photo sensitivity of the films.

Effect of Sodium Selenosulfate Concentration on Microstructural, Morphological, and Luminescence Characteristics of Cadmium Selenide Nanoparticles

CBD-deposited cadmium selenide nanoparticles in acidic medium production at pH value of bath solution was stayed constant at 6.5 using EDTA as complexing agents; sodium selenosulfite acts as a source of Se2- ion and cadmium acetate as source of Cd2+ ion. The nanoparticles of binary compound CdSe were also grown at different concentrations of sodium selenosulfite, and the influence of this parameter on the behaviours of the nanoparticles was studied. The as-synthesized cadmium selenide nanoparticles are investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and PL absorption spectroscopy. Cadmium-selenide nanoparticles were produced using various concentrations as 10, 15, and 20 milliliters on a microscopic glass plate by chemical technique at a growth temperature of 90 degree Celsius. Microstructural constraints realized from the X-ray diffraction pattern decrease in grain size with an increase of concentration (8.25 nm–0.01 nm). It witnessed that the synthesized nanoparticle has a cubic crystal structure with favoured direction towards the (111) Miller indices’ plane. The oriented peak was investigated from the planes (311) and (111). From patterns of PL emissions, it was detected that in increasing concentration of sodium selenosulfate intensity, the nanoparticles with small crystal size could represent maximum luminescence intensity associated with the larger crystal size. This is due to the fact that the amount of ions on the nanoparticle surface rapidly increases as the crystal size of the nanoparticles reduces. Additionally, the transporter recombination ratio was increased as the size of the transporter reduces resulting in an increase in the overlap between the electron and hole wave functions. SEM inspection of produced nanoparticles reveals that the surface is free of cracks and that the grains are spherically formed. The surface is coated with granules of consistent size and shape. There are no fractures or holes visible inside the thin films under examination.

Quantum-chemical modeling of the processes of cadmium sulfide and cadmium selenide films synthesis in aqueous solutions

The quantum-chemical modeling of the synthesis process chemistry of CdS and CdSe in aqueos solutions was carried out. For that reason, the CdS synthesis simulation was carried out through the formation of Cd(II) complex forms with the trisodium citrate and ammonium hydroxide. At the CdSe synthesis, the sodium selenosulfate with and without trisodium citrate was used. It was established that this process passes through several intermediate stages with the transitional reactive complexes formation. On the basis of obtained data, the energy stages diagrams are constructed and the comparison of CdS and CdSe synthesis processes with various complexing agents has been carried out. The CdS and CdSe films were obtained by chemical synthesis method from an aqueous solution of cadmium salt, complexing and chalcogenizing agents. X-ray phase analysis confirmed the formation of desired compounds, which was predicted by modeling.

Thickness modulated opto-electronic properties of SnSe thin films prepared by CBD

SnSe (Tin Selenide) thin films were fabricated from the tin chloride and sodium selenosulphate precursors of Sn2+ and Se2− ions by Chemical bath deposition. The thin films of varying thickness from 80 nm to 180 nm, were grown on glass substrate. X-ray diffraction technique is used to find out structure and crystalline size of the desired film. Surface morphology &elemental composition of the deposited films are investigated with the help of scanning electron microscopy (SEM) and EDAX.

Morphology, Structure, and Optical Properties of Nanocrystalline CdSe Films Doped with Copper

Nanocrystalline CdSe films on a frosted glass substrate are synthesized via hydrochemical deposition with sodium selenosulfate using an additive of 5 × 10–4–10–3 mol/L copper(II) chloride. It is found that introducing copper(II) chloride into the reaction mixture accelerates the formation of solid phase CdSe and thins the cadmium selenide layer from 240 to 130–160 nm. It is established that doping with copper does not affect the cubic B3 structure (space group $$F\bar {4}3m$$ ) of the CdSe film, but 10−3 mol/L copper(II) chloride in the reactor reduces the period of the crystal lattice from 0.59967 to 0.59899 nm, due to the formation of supersaturated substitutional solid solution CuxCd1−xSe (x = 0.03). The band gap of the CdSe film, calculated according to light transmittance and diffuse reflectance, is 1.8 eV. Adding copper to the film lowers Еg to 1.6 eV. It is shown that doping with copper results in luminescence in the near-IR spectral range (680–780 nm) and changes conductivity from the n to the p type.

Structural and Surface morphology of Lead Selenide (PbSe) thin films

Lead Selenide (PbSe) thin films are deposited by chemical bath deposition for 2 hours in different temperature. The precursors used are 0.2M of Lead (II) nitrate, 0.5M of Sodium Selenosulfate, 2.0M of Sodium hydroxide and 4ml of Triethanolamine. The film deposition is carried out at 50°C, 60°C, 70°C, and 80°C for 2 hours. The thickness of the film varied in the range from 1400 to 5200Å. The structural characterization of these films is carried out by X–ray diffractometar (JEOL-Japan, JDX 8030 model). The XRD pattern of PbSe films deposited at different temperature exhibit the polycrystalline structure. In the present study, Scanning Electron Microscope (JOEL 840 SEM/EDAX) is employed to analyze the surface morphology of the films. In addition, the compositions of the films are estimated from EDAX Spectrum. Therefore, it is observed that the films deposited in this work, possess strong peaks for Pb and Se and no other impurities are detected through the EDAX Spectrum, confirming high purity of the PbSe thin film.

Сравнительные кинетические исследования химического осаждения PbSe селеносульфатом натрия и селеномочевиной с установлением влияния их природы на состав и морфологию пленок

After analyzing the literature, one can note the increased interest in lead selenide in the thin-film state, used in various fields: from microelectronics to solar energy converters. There are physical and chemical methods for producing PbSe films, each of which has its own advantages and disadvantages. However, researchers prefer chemical deposition from aqueous media, which eliminates the need for complex, expensive equipment, heating to high temperatures and creating high pressures. The Ural school of thin-film synthesis has developed and tested a kinetic-thermodynamic method for predicting the chemical deposition of metal chalcogenides. The thermodynamic assessment carried out in our previous publication indicated only the principal possibility of the formation of lead selenide when using selenocarbamide СSe(NH2)2 and sodium selenosulfate Na2SeSO3. For a more complete understanding of this process, a comprehensive approach is necessary, taking into account the patterns of the deposition of the solid phase of PbSe in time, depending on thermodynamic factors - temperature and concentration of reagents. Therefore, in this work, we studied the kinetics of the chemical deposition of lead selenide with selenourea and sodium selenosulfate from solutions containing lead acetate, sodium citrate, ammonium hydroxide and iodide, in the temperature 303 -353 K under conditions of spontaneous nucleation of the solid phase. As a result of the studies, the partial kinetic reaction orders for chalcogenizers were determined, amounting to 0.86 (СSe(NH2)2) and 0.78 (Na2SeSO3), as well as the activation energy of the formation of lead selenide, which amounted to 45.1 and 25.07 kJ/mole, respectively. Hydrochemical deposition of selenocarbamide and sodium selenosulfate produced PbSe films on substrates of sitall and glass with a thickness of 200-300 nm. Energy dispersive analysis and scanning electron microscopy showed the influence of the nature of the substrate, type chalcogenizer on the morphology, particle size distribution and elemental composition of lead selenide layers. An elemental analysis showed that PbSe films precipitated with sodium selenosulfate contain an excess of lead compared to selenium (Pb/Se = 1.25-1.32), and the stoichiometric composition ensures the use of selenocarbamide (Pb/Se = 0.99-1.05).

Effect of selenisation on the properties of antimony selenide thin films

Antimony Selenide (Sb2Se3) is an important photoconductive semiconductor and it has a band gap of 1.3 eV. It finds applications in solar selective and decorative coating, optical devices and thermoelectric cooling devices. In the present work, Sb2Se3 thin film is prepared by Chemical Bath Deposition (CBD) technique. This method is most suitable for large area samples and it is very simple. Antimony chloride and sodium selenosulfate are used as precursors for the preparation of antimony selenide thin films. It was observed from XPS analysis that antimony oxide was also present as an impurity phase along with antimony selenide. In this work, selenisation is carried out in order to increase the selenium content in the pristine antimony selenide thin films. Selenisation was also done by the method of CBD. These samples were annealed at various temperatures and characterized structurally, morphologically and optically. It was observed that the inclusion of Se has lead to exclusion of oxygen from the surface layers of Antimony Selenide films. Se inclusion has also changed the morphology of Antimony selenide films drastically.

Ultra-small aqueous glutathione-capped Ag-In-Se quantum dots: luminescence and vibrational properties.

We introduce a direct aqueous synthesis of luminescent 2–3 nm Ag–In–Se (AISe) quantum dots (QDs) capped by glutathione (GSH) complexes, where sodium selenosulfate Na2SeSO3 is used as a stable Se2− precursor. A series of size-selected AISe QDs with distinctly different positions of absorption and PL bands can be separated from the original QD ensembles by using anti-solvent-induced size-selective precipitation. The AISe–GSH QDs emit broadband PL with the band maximum varying from 1.65 eV (750 nm) to 1.90 eV (650 nm) depending on the average QD size and composition. The PL quantum yield varies strongly with basic synthesis parameters (ratios of constituents, Zn addition, duration of thermal treatment, etc.) reaching 4% for “core” AISe and 12% for “core/shell” AISe/ZnS QDs. The shape and position of PL bands is interpreted in terms of the model of radiative recombination of a self-trapped exciton. The AISe–GSH QDs reveal phonon Raman spectra characteristic for small and Ag-deficient tetragonal Ag–In–Se QDs. The ability of ultra-small AISe QDs to support such “bulk-like” vibrations can be used for future deeper insights into structural and optical properties of this relatively new sort of QDs.

Гидрохимический синтез пленок халькогенидов металлов. Часть 42. Экспериментальная проверка областей осаждения PbSe селеносульфатом натрия и селеномочевиной в присутствии различных лигандов

Calculation of ionic equilibria in the reaction system for synthesis of PbSe thin films was carried out. Three reaction systems containing the following combinations of reagents were considered: sodium citrate with liquid ammonia and sodium selenosulfate (system 1) or selenourea (system 2) used as chalcogenizer, ethilendiamine, sodium acetate and selenourea (system 3).The main lead complex compoundsprevented the fast PbSe formation in system 1 and 2 in region of pH of intensive selenosulfate and selenourea decomposition were hydroxo-citrate complexes. In the system 3 complexes with ethilendiamine and acetate-ions played the most significant role. For evaluating the deposition conditions of the main and impurity phases (metal hydroxides and cyanamides) by thermodynamic calculations taking into account the sizes of critical nucleis, the boundary conditions and regions of formation of PbSe, Pb(OH)2, PbCN2 in the studied reaction systems were found. The calculation results are presented in the form of three-dimensional dependencies in the coordinates “indicator of the initial concentration of the metal salt – pH of the solution – ligand concentration” and “indicator of the initial concentration of the metal salt – pH of the solution – concentration of the chalcogenizer”. Based on the calculations and preliminary experiments, the compositions of the discussed reaction mixtures were formed for the chemical bath deposition of PbSe films, which, in addition to the main components, included a dopant in the form of ammonium iodide. In the synthesis process at a temperature of 353 K (system 1 and 2) for 60 minutes and 308 K for 90 minutes (system 3), using all the studied reaction systems on glass substrates, homogeneous PbSe layers with a thickness of ~500 to ~700 nm were obtained. The ratio between the main elements of Pb and Se in the film varies between 0.98-1.32, and the iodine content is 7-11 at.% depending on the composition of the reaction bath.

AMORPHOUS PbSe THIN FILM PRODUCED BY CHEMICAL BATH DEPOSITION AT pH OF 5–8

Lead selenide (PbSe) thin films have been deposited on amorphous glass substrates at room temperature, using the simple chemical bath deposition technique. Lead sulfate and sodium selenosulfate were used as the source materials to obtain lead selenide films. Transmittance, absorption, optical bandgap and refractive index of the films were investigated via the UV–vis spectrum. Amorphous form was observed in the XRD pattern. The structural and optical properties of PbSe thin films produced at different pH were analyzed. SEM analysis was performed for analyzing the surface of the films. Some properties of the films were observed to vary with pH and these properties were investigated according to the change of pH, for pH values of 5–8. Optical bandgap varied with pH between 1.46[Formula: see text]eV and 1.75[Formula: see text]eV. Film thickness also changed with pH from 465[Formula: see text]nm to 1765[Formula: see text]nm.

Morphology and Thermal Stability of Thin Cu1.8Se Films Produced by Chemical Deposition

We have studied the morphology and thermal stability of thin Cu1.8Se films produced by hydrochemical deposition at 333 K using sodium selenosulfate. The crystal structure and phase composition of the films have been determined by X-ray diffraction and scanning electron microscopy. Heat treatment in the temperature range 453–563 K has been shown to change the phase composition and morphology of the copper(I) selenide films, as well as the size of their structural elements.