Se Ratio Research Articles

Essential and non-essential elements in the endemic Peppered catshark Galeus piperatus of deep-ocean waters from northern Gulf of California: Baseline levels and Se ratios

In this study the levels of As, Cd, Cu, Hg, Pb, Se, Zn and Se:Hg molar ratios, in muscle and liver of the endemic catshark Galeus piperatus from the northern Gulf of California (NGC) and relationships with biological parameters, were determined. Arsenic presented the highest levels for both tissues and Pb the lowest. The Se:Hg molar ratios were >1. Sex was not a determining factor in accumulation of elements. The differences in the levels of the studied elements between tissues might be due to their physiological functions and the availability of the metal(loid)s. The diet was considered as an important contribution pathway of these elements despite the fact that G. piperatus feeding habits are still unknown. More research is necessary to clearly understand the interactions between the biology of G. piperatus and the bioavailability of the studied elements and use this endemic shark species as a potential deep-sea biomonitor in NGC.

Enhanced ICP-MS detection of 24 elemental impurities in complex, high matrix mineral, medicinal lanthanum carbonates according to ICH Q2 (R2).

Validation of the specificity of ICP-MS methods by ICH Q2 (R2) through spiking experiments cannot characterize the multi-atomic interference of complex high matrix samples, possibly affecting the accuracy of the method and reliability of results. In this study, we highlight this issue by investigating the elemental impurities in lanthanum carbonate raw materials and use isotope ratio analysis to overcome this limitation and establishing an accurate ICP-MS method for 24 elemental impurities (listed in ICH Q3D). An Agilent 7900 ICP-MS was used with an automatic sampler for sample determination in the He mode. The isotope ratio of elemental impurities in the spiked samples was analyzed to characterize polyatomic interference and select the exclusive mass number of elemental impurities. While the recovery rate of most elemental impurities met the requirements, that of selenium (default measurement mass number 78Se) exceeded the standard in the matric sample. The isotope ratio of Se (78Se/82Se) was much higher than the theoretical value, indicating that the response intensity of m/z 78 was formed by the combination of 78Se and other mass-to-charge ratios, such as LaOH2+ formed by the large amount of La in the matrix. Therefore, 82 was chosen as the mass number for Se. The validation results indicate that the method has strong specificity, high accuracy, and is simple and facile. This study provides technical support for the control of elemental impurities in lanthanum carbonates and isotope ratios can be used as a supplementary means of spiked recovery rates.

Fabrication, characterization, and in vitro studies of Selenium-substituted hydroxyapatite coatings

Abstract The increasing demand for hydroxyapatite (HA) coatings with enhanced functionality have led to novel materials with compositions that are more closely resembling those of natural bone apatites. In the present study, selenium-substituted (Se–HA) powders with various Se quantities were prepared by chemical precipitation. By applying suspension plasma spray (SPS), the surface of Ti substrates was coated with corresponding Se-HA coatings. The microstructural and physicochemical properties of the powders and the coatings were studied. Analysis by x-ray diffraction indicates that SeO3 2− replaced the PO4 3− groups, affecting the crystal structure and crystallinity of HA. As the extent of Se substitution increases, the lattice volume expands and the crystallinity decreases. The synthesized Se-HA powders were confirmed to be calcium-deficient apatite through energy-dispersive x-ray spectroscopy. However, the high temperature of SPS accelerated volatilization of P, increasing the Ca/(P + Se) ratio of the coatings, whereas the chemical valence state of Se remained unchanged. The Se–HA coating exhibited a high bonding strength of >33 MPa, fully meeting the requirement of 15 MPa as coating implant materials. Dissolution behavior tests indicate that the Se–HA coatings had high solubility in comparison to the HA coating. As the substitution degree of Se increased, the dissolution rate also increased, which greatly enhanced the capacity to generate a bone-like apatite layer. In vitro cell experiments indicate that the Se–HA coatings exhibited excellent biocompatibility, and facilitated adhesion and proliferation of osteoblast MC3T3-E1, even in the presence of fluorine. Furthermore, antibacterial properties of Se–HA coatings were also indicated by inhibition of Staphylococcus aureus, which is the main cause of most infections after orthopedic surgeries. Thus, the Se–HA coatings have potential as implant coating materials for orthopedic applications.

Trophic stoichiometry of macroelements and metals in a terrestrial food web

In order to understand the transfer of macroelements and toxic metals in the terrestrial food web, barn swallows, terrestrial frogs, and insects were collected from farmlands in the Leizhou Peninsula, and analyzed for macroelements carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) and trace metals nickel (Ni), zinc (Zn), selenium (Se), copper (Cu), chromium (Cr), cadmium (Cd), lead (Pb), and mercury (Hg). The multi-element ecological stoichiometry was discussed to trace the food web flow of nutrients and toxicants. The percentage contents of C, N, P, and S were 35.43–59.91%, 6.89–12.11%, 0.49–4.66%, and 0.44–2.19%, respectively. The concentrations of Ni, Zn, Se, Cu, Cr, Cd, Pb, and Hg were 0.163–116 mg/kg, 38.7–227 mg/kg, 0.0453–3.82 mg/kg, 3.11–141 mg/kg, not detected—79.6 mg/kg, 0.0203–0.358 mg/kg, 0.148–4.57 mg/kg, and 0.00159–1.46 mg/kg, respectively. Organisms at high trophic levels had higher contents of N, P, and S, and lower contents of C. Significant correlations were observed between δ15N and ratios of C: N, C: P, C: S, N: P, N: S, and S: P, indicating selective transfer of biogenic elements for predators in the terrestrial food web. Most metals including Ni, Zn, Se, Cu, Cr, Pb, and Hg had biomagnification factors and trophic magnification factors higher than 1, because the whole body of organisms rather than tissues were used. The negative correlations between the detoxification ratios of Se: X (each toxic metal) and metal concentrations suggest potential adverse effect of metals on terrestrial organisms.

The potency of Monascus purpureus to achieve the transformation from inorganic selenium into organic selenium during the fermentation process

Selenium (Se), as an essential element for the human body, cannot be produced by itself, making Se-rich products research a current hotspot. Microorganisms are common Se-rich carriers and previous experiments mainly focused on yeast and lactic acid bacteria, lacking mold. In this study, the total Se and organic Se content in Monascus purpureus (M. purpureus) were determined by a liquid chromatography-atomic fluorescence spectrometry after fermentation, applying inorganic sodium selenite as exogenous Se. The research results indicated that M. purpureus successfully converted inorganic Se into organic Se, with an organic Se to total Se ratio of 30.50%, 36.14%, 39.94%, 46.18%, and 53.00% at 2, 4, 6, 8, and 10 mg/L sodium selenite, respectively. The proportion of Se-protein (28.04%–47.33%) was highest in organic Se, especially water-soluble Se-protein, followed by Se-polysaccharide (3.80%–5.07%) and Se-nucleic acid (1.84%–3.07%). Furthermore, Se-enriched treatment did not significantly alter the morphology or structure of M. purpureus, while enriching the types and content of volatile components in the fermentation broth. Thus, this study was expected to lay the foundation for the development and utilization of Se-rich M. purpureus products.

CAF-Associated Genes in Breast Cancer for Novel Therapeutic Strategies.

Breast cancer (BC) is the most common cancer in women, and therapeutic strategies for it are based on the molecular subtypes of luminal BC, HER2 BC, and triple-negative BC (TNBC) because each subtype harbors different unique genetic aberrations. Recently, features of the tumor microenvironment (TME), especially cancer-associated fibroblasts (CAFs), have been demonstrated to play a critical role in BC progression, and we would like to understand the molecular features of BC CAFs for novel therapeutic strategies. In a recent study, 115 CAF-associated genes (CAFGs) were identified in a public database of microdissection and microarray data (GSE35602) from 13 colorectal cancer (CRC) tumors. Using a public database (GSE10797) of 28 BC tumors, a similar analysis was performed. In BC, 59 genes from the 115 CAFGs identified in CRC (CRC CAFGs) were also closely associated with a CAFs marker, SPARC (R = 0.6 or beyond), and POSTN was of particular interest as one of the BC CAFGs with the highest expression levels and a close association with SPARC expression (R = 0.94) in the cancer stroma of BC tumors. In BC stroma, POSTN was followed in expression levels by DKK3, MMP2, PDPN, and ACTA2. Unexpectedly, FAP and VIM were not as highly associated with SPARC expression in the cancer stroma of BC tumors and exhibited low expression. These findings suggested that ACTA2 might be the most relevant conventional CAFs marker in BC, and ACTA2 was actually correlated in expression with many CRC CAFGs, such as SPARC. Surprisingly, the SE ratio values of the BC CAFGs were much lower (average SE = 3.8) than those of the CRC CAFGs (SE = 10 or beyond). We summarized the current understanding of BC CAFs from the literature. Finally, in triple-negative BC (TNBC) (n = 5), SPARC expression uniquely showed a close association with COL11A1 and TAGLN expression, representing a myofibroblast (myCAFs) marker in the cancer stroma of the BC tumors, suggesting that myCAFs may be molecularly characterized by TNBC in contrast to other BC phenotypes. In summary, CAFs could have unique molecular characteristics in BC, and such TME uniqueness could be therapeutically targeted in BC.

Reaction-dependent optical behavior and theoretical perspectives of colloidal ZnSe quantum dots

Colloidal quantum dots (QDs) are attracting research interest because of their unique optical properties that result from the quantum confinement effect. ZnSe QDs, which are II–VI semiconductors, offer a wide direct bandgap (2.7 eV), making them promising for applications such as light-emitting diodes, photodetectors, and biomedical labeling. In the present work, colloidal ZnSe (QDs) were synthesized by the hot-injection method with a Zn:Se ratio of 1:1. The optical properties of ZnSe QDs obtained at different reaction times were investigated by spectrophotometric UV–vis absorption and emission measurements. The as-synthesized ZnSe QDs exhibit blue excitonic emission, and no defect emission was detected. Transmission electron micrographs indicated that the QDs have a spherical morphology with dimensions ranging from 3.69 to 4.53 nm. In particular, the Brus model was applied to demonstrate a correlation between the QD sizes and the optical bandgaps obtained from Tauc plots.

Selenium-Doped Nanoheterojunctions for Highly Efficient Cancer Radiosensitization.

Exploring efficient and low-toxicity radiosensitizers to break through the bottleneck of radiation tolerance, immunosuppression and poor prognosis remains one of the critical developmental challenges in radiotherapy. Nanoheterojunctions, due to their unique physicochemical properties, have demonstrated excellent radiosensitization effects in radiation energy deposition and in lifting tumor radiotherapy inhibition. Herein, they doped selenium (Se) into prussian blue (PB) to construct a nano-heterojunction (Se@PB), which could promote the increase of Fe2+/Fe3+ ratio and conversion of Se to a high valence state with Se introduction. The Fe2+-Se-Fe3+ electron transfer chain accelerates the rate of electron transfer on the surface of the nanoparticles, which in turn endows it with efficient X-ray energy transfer and electron transport capability, and enhances radiotherapy physical sensitivity. Furthermore, Se@PB induces glutathione (GSH) depletion and Fe2+ accumulation through pro-Fenton reaction, thereby disturbs the redox balance in tumor cells and enhances biochemical sensitivity of radiotherapy. As an excellent radiosensitizer, Se@PB effectively enhances X-ray induced mitochondrial dysfunction and DNA damage, thereby promotes cell apoptosis and synergistic cervical cancer radiotherapy. This study elucidates the radiosensitization mechanism of Se-doped nanoheterojunction from the perspective of the electron transfer chain and biochemistry reaction, which provides an efficient and low-toxic strategy in radiotherapy.

CAFs-Associated Genes (CAFGs) in Pancreatic Ductal Adenocarcinoma (PDAC) and Novel Therapeutic Strategy.

Pancreatic ductal adenocarcinoma (PDAC) is the most aggressive cancer with striking fibrosis, and its mortality rate is ranked second across human cancers. Cancer-associated fibroblasts (CAFs) play a critical role in PDAC progression, and we reviewed the molecular understanding of PDAC CAFs and novel therapeutic potential at present. CAFs-associated genes (CAFGs) were tentatively classified into three categories by stroma specificity representing stroma/epithelia expression ratios (SE ratios). The recent classification using single cell transcriptome technology clarified that CAFs were composed of myofibroblasts (myCAFs), inflammatory CAFs (iCAFs), and other minor ones (e.g., POSTN-CAFs and antigen presenting CAFs, apCAFs). LRRC15 is a myCAFs marker, and myCAFs depletion by diphtheria toxin induces the rapid accumulation of cytotoxic T lymphocytes (CTLs) and therefore augment PDL1 antibody treatments. This finding proposes that myCAFs may be a critical regulator of tumor immunity in terms of PDAC progression. myCAFs are located in CAFs adjacent to tumor cells, while iCAFs marked by PDPN and/or COL14A1 are distant from tumor cells, where hypoxic and acidic environments being located in iCAFs putatively due to poor blood supply is consistent with HIF1A and GPR68 expressions. iCAFs may be shared with SASP (secretion-associated phenotypes) in senescent CAFs. myCAFs are classically characterized by CAFGs induced by TGFB1, while chemoresistant CAFs with SASP may dependent on IL6 expression and accompanied by STAT3 activation. Recently, it was found that the unique metabolism of CAFs can be targeted to prevent PDAC progression, where PDAC cells utilize glucose, whereas CAFs in turn utilize lactate, which may be epigenetically regulated, mediated by its target genes including CXCR4. In summary, CAFs have unique molecular characteristics, which have been rigorously clarified as novel therapeutic targets of PDAC progression.

Investigating and optimizing the variation of selenium infused MoS2 as electrode material for supercapacitor applications

Molybdenum disulfide (MoS2) has been immensely explored for its potential usage in energy storage applications owing to its high theoretical specific capacitance and layered structure. Here, we have investigated the effect of selenium addition in MoS2 forming MoS2(1-x)Se2x alloys and studied their electrochemical performance. Selenization was performed through a simple hydrothermal method. The electrochemical performance of MoS1Se1 was evaluated in a two-electrode configuration. The selenization is found to improve the electrochemical performance of MoS2 and the MoS1Se1 alloy with the optimal S (sulfur) to Se (selenium) ratio of 1:1 exhibits an excellent areal capacitance of 2629.45 mF/cm2 at 1 mA/cm2, with an appreciable specific capacitance of 266.51 F/g at a current density of 0.5 A/g and excellent cycle stability of 81.64 % after 6000 cycles. Along with the experimental findings, Density functional theory calculations were also performed, revealing that the electronic properties of MoSSe systems can be tuned by varying the ratio of S and Se.

Unveiling Crucial Chemical Processing Parameters Influencing the Performance of Solution-Processed Inorganic Thermoelectric Materials.

Production of thermoelectric materials from solution-processed particles involves the synthesis of particles, their purification and densification into pelletized material. Chemical changes that occur during each one of these steps render them performance determining. Particularly the purification steps, bypassed in conventional solid-state synthesis, are the cause for large discrepancies among similar solution-processed materials. In present work, the investigation focuses on a water-based surfactant free solution synthesis of SnSe, a highly relevant thermoelectric material. We show and rationalize that the number of leaching steps, purification solvent, annealing, and annealing atmosphere have significant influence on the Sn : Se ratio and impurity content in the powder. Such compositional changes that are undetectable by conventional characterization techniques lead to distinct consolidated materials with different types and concentration of defects. Additionally, the profound effect on their transport properties is demonstrated. We emphasize that understanding the chemistry and identifying key chemical species and their role throughout the process is paramount for optimizing material performance. Furthermore, we aim to demonstrate the necessity of comprehensive reporting of these steps as a standard practice to ensure material reproducibility.

Unveiling Crucial Chemical Processing Parameters Influencing the Performance of Solution‐Processed Inorganic Thermoelectric Materials

AbstractProduction of thermoelectric materials from solution‐processed particles involves the synthesis of particles, their purification and densification into pelletized material. Chemical changes that occur during each one of these steps render them performance determining. Particularly the purification steps, bypassed in conventional solid‐state synthesis, are the cause for large discrepancies among similar solution‐processed materials. In present work, the investigation focuses on a water‐based surfactant free solution synthesis of SnSe, a highly relevant thermoelectric material. We show and rationalize that the number of leaching steps, purification solvent, annealing, and annealing atmosphere have significant influence on the Sn : Se ratio and impurity content in the powder. Such compositional changes that are undetectable by conventional characterization techniques lead to distinct consolidated materials with different types and concentration of defects. Additionally, the profound effect on their transport properties is demonstrated. We emphasize that understanding the chemistry and identifying key chemical species and their role throughout the process is paramount for optimizing material performance. Furthermore, we aim to demonstrate the necessity of comprehensive reporting of these steps as a standard practice to ensure material reproducibility.

Synergistically optimized electron and phonon transport in high-performance copper sulfides thermoelectric materials via one-pot modulation

Optimizing thermoelectric conversion efficiency requires the compromise of electrical and thermal properties of materials, which are hard to simultaneously improve due to the strong coupling of carrier and phonon transport. Herein, a one-pot approach realizing simultaneous second phase and Cu vacancies modulation is proposed, which is effective in synergistically optimizing thermoelectric performance in copper sulfides. Multiple lattice defects, including nanoprecipitates, dislocations, and nanopores are produced by adding a refined ratio of Sn and Se. Phonon transport is significantly suppressed by multiple mechanisms. An ultralow lattice thermal conductivity is therefore obtained. Furthermore, extra Se is added in the copper sulfide for optimizing electrical transport properties by inducing generating Cu vacancies. Ultimately, an excellent figure of merit of ~1.6 at 873 K is realized in the Cu1.992SSe0.016(Cu2SnSe4)0.004 bulk sample. The simple strategy of inducing compositional and structural modulation for improving thermoelectric parameters promotes low-cost high-performance copper sulfides as alternatives in thermoelectric applications.

Employing pre-annealing as a control tool for alloying in CdSeTe/CdTe stacks produced by evaporation in vacuum

Alloying plays a critical role in CdSeTe/CdTe stacks used as absorber structure in high efficiency solar cells. In this study, the effect of pre-annealing between CdSeTe and CdTe on the structural and optical properties of stacks was examined in detail. After the CdSeTe layers (before CdTe) were grown by vacuum evaporation, pre-annealing was applied at moderate temperatures in the range of 200°C–300 °C. According to both XRD patterns and Raman spectra, a clear effect of pre-annealing temperature on alloying ratios and phase formations between CdSeTe and CdTe was ascertained. It was observed from the surface images that the change in pre-annealing temperature affected the grain sizes and morphology, depending on the Se ratios in the alloying. It was found that the transmission spectrum shifted to the long wavelength region with the change in crystallization as a result of pre-annealing. In the PL spectra, the presence of transitions related to the phase structures revealed by the XRD results was detected. In consequence, pre-annealing at 250 °C presented more promising results for potential CdTe cell applications.

Improving the performance of Cu2ZnSn(S,Se)4 thin film solar cells by SCAPS simulation

The effect of Se/(S + Se) ratio, absorber thickness, series and shunt resistance on Cu2ZnSn(S,Se)4 (CZTSSe) solar cells were studied by one-dimensional solar cell capacitance simulator (SCAPS-1D). The efficiency exhibited an initial increase followed by a subsequent decrease as Se/(S + Se) ratio increased, achieving peak efficiency of 17.38 % at Se/(S + Se) ratio of 0.2. As absorber thickness increased from 0.5 to 1.5 μm, both the short circuit current and efficiency exhibited continuous improvement, which was attributed to the enhanced absorption and utilization of sunlight. However, when the thickness of absorber exceeded 1.5 μm, the transport of carriers across the absorber was difficult due to the excessive thickness, and the efficiency was almost not improved. The optimal device possessed efficiency of 17.91 %. Series resistance exerted a more substantial influence on efficiency than shunt resistance. To achieve high-efficiency CZTSSe devices, series resistance should be controlled below 2 Ω·cm2, and shunt resistance should be controlled above 600 Ω·cm2.

Tailored Band Alignment for Improved Carrier Transport in Composition-Controlled Sb2(S,Se)3.

Sb2(S,Se)3 is a highly available energy material with a tunable bandgap by adjusting the S/Se ratio. Increasing the Se ratio can enhance the efficiency of Sb2(S,Se)3 solar cells, with a higher short-circuit current (JSC). However, the accompanying decrease in the open-circuit voltage (VOC) restricts further improvement. The defect passivation is important, since it can reduce carrier recombination, enhancing the VOC. In this study, the relevance of the S/Se ratio, defect concentration, and VOC was investigated. The samples with or without the deposition of Se-rich Sb2(S,Se)3 onto S-rich Sb2(S,Se)3 were used for defect characterization. Different surface compositions were confirmed by Raman spectroscopy. The complicated subdefect states of S-rich Sb2(S,Se)3 were shown through photoluminescence and conductive atomic force microscopy, and a decrease in the defect concentration was observed through surface photovoltage. The improvement of JSC via bandgap grading and the simultaneous VOC improvement by defect passivation resulted in efficient cell performance.

Synergistic effects of Core@Shell (CZTS@CZTSe) on photovoltaic & photocathode applications

Nanotechnology has undergone significant advancements attributable to the synthesis of nanoparticles (NPs), reflecting the collaborative endeavours of numerous researchers. This investigation contributes to the field by fabricating core–shell (Csh) NPs composed of CZTS (Cu2ZnSnS4)-CZTSe(Cu2ZnSn(SSe)4), exhibiting potential applications as photocatalysts for water treatment and photocathodes for solar cells. Utilizing the innovative “Hot-Injection” method in NP synthesis represents a noteworthy breakthrough, facilitating a reduction in reaction time and enabling precise control over morphology. Characterization employing diverse techniques has unveiled noteworthy structural and electrochemical properties. This includes the identification of a Kesterite phase with varying S and Se ratios, as well as binary/ternary phases influencing purity. UV–vis absorbance spectroscopy has provided insights into electronic properties, while electrochemical impedance spectroscopy has indicated the low charge transfer resistance (Rct) of the CZTS80Se20 core–shell structure, positioning it as a prime candidate for application procedures. Photocatalytic efficiency assessment involved subjecting the NPs to Methylene blue dye under visible light, resulting in a maximum efficiency of 99.9% within a certain range of catalyst concentrations. This study also demonstrated the NP’s suitability as absorber layers of optimal thickness in solar cells, deposited through the Electrophoretic Deposition (EPD) technique. Linear and symmetric I-V response results indicate the ohmic nature of the contacts. This research represents a significant stride forward, unveiling promising prospects for the utilisation of core–shell CZTS-CZTSe NPs across.

Hematological Parameters of Patients Positive for Coronavirus With and Without Comorbidities.

The causative agent of the coronavirus disease (COVID-19) is a virus from the SARS-CoV-2 group of viruses that cause severe acute respiratory syndrome. The aim of the study was to examine the differences in hematological analyses of patients suffering from COVID-19 with and without comorbidities, to determine the degree of the clinical picture based on the MEWS scale and to examine the persistence of inflammatory parameters with the severity of the clinical picture. The research is a cross-sectional retrospective study, conducted in the laboratory diagnostics service of Tesanj General Hospital. It included 211 respondents positive for the coronavirus in the Tesanj General Hospital. The degree of severity of the clinical picture was determined on the basis of the MEWS scale. A total of 211 patients positive for coronavirus participated in the study, of which 61.1% (129) were male and 38.9% (82) were female. Based on the results, a statistically significant difference was found in the ratio of hematological parameters in subjects with and without comorbidities (p < 0.05). A strong positive correlation was found between the ratio of SE and D-dimer in subjects and the degree of severity of the clinical picture. A statistically significant difference was recorded in the ratio of hematological parameters (lymphocytes, granulocytes, erythrocytes, hematocrit, and APTT) in subjects with and without comorbidities in all three of the observed groups (p < 0.05), while there were no statistically significant differences in other hematological parameters (p > 0.05).

Solution-processed Sb2Se3 photocathodes under Se-rich conditions and their photoelectrochemical properties.

In this study, selenium (Se)-rich antimony selenide (Sb2Se3) films were fabricated by applying a solution process with the solvents ethylenediamine and 2-mercaptoethanol to optimize the photoelectrochemical (PEC) performance of the Sb2Se3 photocathode. Various antimony (Sb)-Se precursor solutions with different molar ratios of Sb and Se (Sb : Se = 1 : 1.5, 1 : 3, 1 : 4.5, 1 : 7.5, and 1 : 9) were prepared to attain Se-rich fabrication conditions. As a result, the Se-rich Sb2Se3 films fabricated using the Sb-Se precursor solution with a molar ratio of Sb : Se = 1 : 7.5 exhibited an improved PEC performance, compared to the stoichiometric Sb2Se3 film. The charge transport was improved by the abundant Se element and thin selenium oxide (Se2O3) layer in the Se-rich Sb2Se3 film, resulting in a decrease in Se vacancies and substitutional defects. Moreover, the light utilization in the long wavelength region above 800 nm was enhanced by the light-trapping effect because of the nanowire structure in the Se-rich Sb2Se3 film. Hence, the optimal Se-rich Sb2Se3 photocathodes showed an improved photocurrent density of -0.24 mA cm-2 at the hydrogen evolution reaction potential that was three times higher than that of the stoichiometric Sb2Se3 photocathodes (-0.08 mA cm-2).

Composition Engineering for the Content and Distribution of Sb–O, Se, S in Antimony Sulfoselenide Thin Films Using Chemical Bath Deposition for Efficient Solar Cells

Herein, Na2SSeO3 solutions are prepared by hydrothermal method at 140 °C for 8 h using Se powder and Na2SO3 solution (the molar ratios of Se:Na2SO3 = 1:4, 1:5, 1:6) and the chemical composition of Na2SSeO3 solutions is analyzed by X‐ray photoelectron spectroscopy. Sb2S y Se3−y thin films are prepared by chemical bath deposition (CBD) at 90 °C for 5 h and subsequently annealed at 375 °C for 10 min and etched by N‐butyldithiocarbamic acid solution in DMF. The effect of the Na2SSeO3 solution, growth solution volume, etching on the thickness and chemical composition of Sb2S y Se3−y thin films, and the power conversion efficiency (PCE) of the corresponding solar cells is systematically investigated. The result reveals that the Na2SSeO3 solutions may be the mixing solutions containing Na2SSeO3, Na2S2SeO6, Na2S2Se2O6, Na2Se. When the molar ratio of Se:Na2SO3 and growth solution volume is 1:5 and 56 mL and the Sb2S y Se3−y thin films with annealing are etched, the PCE of Sb2S y Se3−y solar cells is 8.00% with spiro‐OMeTAD and 8.43% with spiro‐OMeTAD:TMT‐TTF. The PCE of 8.43% is the highest value for Sb2S y Se3−y solar cells using CBD and demonstrates that the composition engineering is an important strategy for improving the PCE of Sb2S y Se3−y solar cells using CBD.