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![World reserves of a) selenium and b) tellurium. The 2020 data comes from the U.S. Geological Survey (USGS) [80]. c) Price per kilogram of material as a function of time. The time period covers the last 5 years. World consumption of d) selenium and e) tellurium. All data comes from the USGS [80].](profile/Gregory-Guisbiers/publication/351953576/figure/fig1/AS:1028609091325952@1622250926243/World-reserves-of-a-selenium-and-b-tellurium-The-2020-data-comes-from-the-US.jpg)
World reserves of a) selenium and b) tellurium. The 2020 data comes from the U.S. Geological Survey (USGS) [80]. c) Price per kilogram of material as a function of time. The time period covers the last 5 years. World consumption of d) selenium and e) tellurium. All data comes from the USGS [80].
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Selenium and tellurium are both energy critical elements as defined by the American Physical Society and the Materials Research Society. When mixed together, both elements form an alloy. The size-and shape-dependent thermal and optical properties of this alloy are investigated in this manuscript by using nano-thermodynamics and machine learning tec...
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... to their scarcity, they cannot be mined directly and are recovered as by-products of copper refining [5]. Due to the non-homogeneous geographic repartition of copper ores around the world, only a small number of countries have access to most of the world reserves of Se and Te ( Figure 1a, 1b) maintaining their prices above ~$25 per kilogram ( Figure 1c). The worldwide consumption of Se and Te is illustrated on Figure 1d and 1e. ...
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... to their scarcity, they cannot be mined directly and are recovered as by-products of copper refining [5]. Due to the non-homogeneous geographic repartition of copper ores around the world, only a small number of countries have access to most of the world reserves of Se and Te ( Figure 1a, 1b) maintaining their prices above ~$25 per kilogram ( Figure 1c). The worldwide consumption of Se and Te is illustrated on Figure 1d and 1e. ...
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... to the non-homogeneous geographic repartition of copper ores around the world, only a small number of countries have access to most of the world reserves of Se and Te ( Figure 1a, 1b) maintaining their prices above ~$25 per kilogram ( Figure 1c). The worldwide consumption of Se and Te is illustrated on Figure 1d and 1e. Specifically, Se is used essentially for metallurgy (30%), glass manufacturing (25%), agriculture (10%), chemicals (10%), electronics (10%) and some minor other uses (5%). ...
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... energy bandgap of the amorphous and crystalline phases are consequently given by: Se Te 0:04976 and -1.37696 0:10488, respectively [73]. Figure 10d, shows the amorphous and crystalline exciton Bohr radius as given by Eq. 18. The exciton Bohr radius of a semiconductor material is of primary importance to determine the onset of quantum confinement effects. ...
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... using Eq. 20, the energy bandgap of 1 x x Se Te as a function of its chemical composition and size can be calculated and it is illustrated in Figure 11 for the sphere, wire, and film morphologies. ...
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... region where the size is below the exciton Bohr radius, is indicated in grey in Figure 11. The sphere displays the largest size effect compared to the wire and the film because Table 2. ...
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... order to use those nanostructures in solar cells, it has been demonstrated by Zdanowicz et al. [75] that the best energy bandgap to absorb the solar light was ~ 1.39 eV for a cell having only one single absorbing material. Therefore, the green areas in Figure 11 are the most adequate regions to select the nanostructures from. This region corresponds to a chemical composition of Te varying between 20 to 40%. ...
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... region corresponds to a chemical composition of Te varying between 20 to 40%. Above ~2 eV, the region in red in Figure 11, represents the nanostructures that could be used in wide-bandgap semiconductor applications such as biological and chemical sensors [76]. Special consideration should be given to the crystallinity (crystalline or amorphous) and morphology (sphere, wire, and film) when selecting materials for this purpose. ...
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... abundances of 0.130 ppm (ref. 3) and 0.001 ppm, 4 respectively. Due to their scarcity, they cannot be mined directly and are recovered as by-products of copper rening. 5 Due to the non-homogeneous geographic repartition of copper ores around the world, only a small number of countries have access to most of the world reserves of Se and Te ( Fig. 1a and b) maintaining their prices above $$25 per kilogram (Fig. 1c). The worldwide consumption of Se and Te is illustrated in Fig. 1d and e. Specically, Se is used essentially for metallurgy (30%), glass manufacturing (25%), agriculture (10%), chemicals (10%), electronics (10%) and some other minor uses (5%), while Te is used for solar ...
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... Due to their scarcity, they cannot be mined directly and are recovered as by-products of copper rening. 5 Due to the non-homogeneous geographic repartition of copper ores around the world, only a small number of countries have access to most of the world reserves of Se and Te ( Fig. 1a and b) maintaining their prices above $$25 per kilogram (Fig. 1c). The worldwide consumption of Se and Te is illustrated in Fig. 1d and e. Specically, Se is used essentially for metallurgy (30%), glass manufacturing (25%), agriculture (10%), chemicals (10%), electronics (10%) and some other minor uses (5%), while Te is used for solar cells (40%), thermoelectrics (30%), metallurgy (15%), rubber ...
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... as by-products of copper rening. 5 Due to the non-homogeneous geographic repartition of copper ores around the world, only a small number of countries have access to most of the world reserves of Se and Te ( Fig. 1a and b) maintaining their prices above $$25 per kilogram (Fig. 1c). The worldwide consumption of Se and Te is illustrated in Fig. 1d and e. Specically, Se is used essentially for metallurgy (30%), glass manufacturing (25%), agriculture (10%), chemicals (10%), electronics (10%) and some other minor uses (5%), while Te is used for solar cells (40%), thermoelectrics (30%), metallurgy (15%), rubber manufacturing (5%) and some other minor uses (10%). Currently, there is ...
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... Te x at the composition x. E Se g (eV) and E Te g (eV) are the energy bandgap of Se and Te, respectively. b is the bowing parameter. The data gathered from ref. 21 suggest that b equals zero (i.e. b amorphous ¼ 0) when Se 1Àx Te x is amorphous, and as such its energy bandgap exhibits a linear dependence with respect to the chemical composition, x (Fig. 10a). When Se 1Àx Te x is crystalline, its energy bandgap does not follow a linear trend anymore but displays bowing characterized by the following bowing factor, b crystalline ¼ 1.102. 72 When crystalline, Se and Te have slightly different energy bandgap values as seen in ref. 72, 1.73 and 0.35 eV, respectively, due to the change in their ...
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... this and with eqn (16a) and (16b), respectively, the refractive index and high-frequency dielectric constant are plotted in Fig. 10b and c, respectively. The refractive index (16a) and high-frequency dielectric constant (eqn (16b)) of Se 1Àx Te x (ref. 73) are modelled using the ...
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... the relationship between the exciton Bohr radius and the energy bandgap established in ref. 73: where a Se-Te B,ex (x) and E Se-Te g,N (x) are the exciton Bohr radius and the bulk energy bandgap of Se 1Àx Te x at a composition x, respectively. x and h are the tting parameters given as 1.04434 AE 0.04976 and À1.37696 AE 0.10488, respectively. 73 Fig. 10d shows the amorphous and crystalline exciton Bohr radius as given by eqn (18). The exciton Bohr radius of a semiconductor material is of primary importance to determine the onset of quantum connement effects. By using eqn (17) and (18), the material's exciton reduced mass, m(x), was determined. In order to achieve this, the exciton ...
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... bandgaps of Se 1Àx Te x at a xed composition, x. In the case of an alloy, a shape (x) becomes composition-dependent. Eqn (20) is valid for sizes larger than the exciton Bohr radius of the material. 36 By using eqn (20), the energy bandgap of Se 1Àx Te x as a function of its chemical composition and size can be calculated and it is illustrated in Fig. 11 for the sphere, wire, and lm morphologies. The region where the size is below the exciton Bohr radius, is indicated in grey in Fig. 11. The sphere displays the largest size effect compared to the wire and the lm because a sphere > a wire > a lm ; see Table 2. In order to use those nanostructures in solar cells, it has been ...
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... for sizes larger than the exciton Bohr radius of the material. 36 By using eqn (20), the energy bandgap of Se 1Àx Te x as a function of its chemical composition and size can be calculated and it is illustrated in Fig. 11 for the sphere, wire, and lm morphologies. The region where the size is below the exciton Bohr radius, is indicated in grey in Fig. 11. The sphere displays the largest size effect compared to the wire and the lm because a sphere > a wire > a lm ; see Table 2. In order to use those nanostructures in solar cells, it has been demonstrated by Zdanowicz et al. 75 that the best energy bandgap to absorb the solar light was $1.39 eV for a cell having only one single ...
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... size effect compared to the wire and the lm because a sphere > a wire > a lm ; see Table 2. In order to use those nanostructures in solar cells, it has been demonstrated by Zdanowicz et al. 75 that the best energy bandgap to absorb the solar light was $1.39 eV for a cell having only one single absorbing material. Therefore, the green areas in Fig. 11 are the most adequate regions to select the nanostructures from. This region corresponds to a chemical composition of Te varying between 20 and 40%. Above $2 eV, the region in red in Fig. 11 represents the nanostructures that could be used in wide-bandgap semiconductor applications such as biological and chemical sensors. 76 Special ...
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... 75 that the best energy bandgap to absorb the solar light was $1.39 eV for a cell having only one single absorbing material. Therefore, the green areas in Fig. 11 are the most adequate regions to select the nanostructures from. This region corresponds to a chemical composition of Te varying between 20 and 40%. Above $2 eV, the region in red in Fig. 11 represents the nanostructures that could be used in wide-bandgap semiconductor applications such as biological and chemical sensors. 76 Special consideration should be given to the crystallinity (crystalline or amorphous) and morphology (sphere, wire, and lm) when selecting materials for this purpose. From Fig. 11, it is clear that ...
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... Special consideration should be given to the crystallinity (crystalline or amorphous) and morphology (sphere, wire, and lm) when selecting materials for this purpose. From Fig. 11, it is clear that nanoparticles are best for wide-bandgap semiconductor applications by comparison to wires or lms. Indeed, wires and lms only appear to be the right material properties to cater to these applications at very small sizes, i.e., below 20 nm, and below 20% Te composition. ...
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... when selecting materials for this purpose. From Fig. 11, it is clear that nanoparticles are best for wide-bandgap semiconductor applications by comparison to wires or lms. Indeed, wires and lms only appear to be the right material properties to cater to these applications at very small sizes, i.e., below 20 nm, and below 20% Te composition. Fig. 12a-d show the transition temperature versus the reduced bandgap energy of Se 1Àx Te x alloys at various sizes (bulk, 50 nm, 10 nm, and 5 nm). The reduced bandgap energy is dened as the observed energy bandgap divided by the target bandgap, which results in the optimal value being 1. For a glassy material, the crystalline temperature is ...
Citations
... . World reserves of selenium (Reproduced with permission from Ref. [3]). ...
... Therefore, selenium has a two-sided effect depending on its concentration ( Figure 2): beneficial at low doses but lethal at high doses. The two sources of selenium for mammalian cells are selenite (SeO 3 -2 ) and selenate (SeO 4 -2 ) from food and water. Selenium is consequently mainly absorbed in the duodenum and caecum by active transport through a sodium pump [6]. ...
... The electron in the conduction band is described by a negative charge (e -), with an effective mass (m e * ), whereas the hole in the valence band is characterized by a positive charge (h + ) with an effective mass (m h * ). The effective mass reflects the increased or decreased mobility of a charge carrier (electron or hole) in [3,18] 0.08-0.25m 0 Electron effective mass [19] 0.25 m 0 Hole effective mass [20] 1.40 m 0 High-frequency dielectric constant [3] 7.3 a semiconductor with respect to that of an electron in vacuum (Table 2). ...
... These include antimicrobial, antioxidative, antifungal, and anticancer properties, along with their ability to serve as drug delivery agents and to assist in bioremediation and bio-recovery. Alloys of Se and Te include similar crystal structures (hexagonal), electronegativity (5.88 and 5.50 eV), valences (+6), and atomic radii (117 and 137), respectively [188]. Both Se and Te are rare in the Earth's crust, with abundances of about 0.05 and 0.001 mg kg −1 , respectively. ...
... These include antimicrobial, antioxidative, antifungal, and anticancer properties, along with their ability to serve as drug delivery agents and to assist in bioremediation and biorecovery. Alloys of Se and Te include similar crystal structures (hexagonal), electronegativity (5.88 and 5.50 eV), valences (+6), and atomic radii (117 and 137), respectively [188]. Both Se and Te are rare in the Earth's crust, with abundances of about 0.05 and 0.001 mg kg −1 , respectively. ...
... Other studies have reported using yeast strains (Yarrowia lipolytica and Trichosporon cutaneum) to produce nano-Te [200]. [188,189,195,201]. ...
The relationship between agriculture and food is very close. It is impossible to produce adequate crops for global food security without proper farm management. Farming practices represent direct and indirect controlling factors in terms of global food security. Farming management practices influence agro-food production from seed germination through to the post-harvest treatments. Nano-farming utilizes nanotechnologies for agricultural food production. This review covers four key components of nano-farming: nano-mushroom production, protein-based nanoparticles, nano-nutrients, and nanofibers. This provides a comprehensive overview of the potential applications of nanotechnology in agriculture. The role of these components will be discussed in relation to the challenges faced and solutions required to achieve sustainable agricultural production. Edible mushrooms are important to food security because they are a nutritious food source and can produce nanoparticles that can be used in the production of other food sources. Protein-based nanoparticles have considerable potential in the delivery of bioactives as carriers and other applications. Nano-nutrients (mainly nano-selenium, nano-tellurium and carbon nanodots) have crucial impacts on the nutrient status of plant-based foods. Carbon nanodots and other carbon-based nanomaterials have the potential to influence agricultural crops positively. There are promising applications of nanofibers in food packaging, safety and processing. However, further research is needed to understand the impacts and potential risks of nanomaterials in the food production system.
... At the same time, in the analysis of phase equilibria in systems of a small volume, it is necessary to take into account several characteristic features. These peculiarities manifest themselves in significant dependences of mutual solubilities of components and equilibrium volume fractions of coexisting phases on the volume [9][10][11][12][13][14][15][16][17][18][19][20], shape of a nanoparticle [12][13][14]18], thermodynamical characteristics of the surrounding environment [20] and several other factors [15,17,19]. The equilibrium phase compositions of small-volume systems are significantly different from the phase compositions of the same systems in the bulk state and can be modeled using the methods of equilibrium chemical thermodynamics [21] and several other approaches [22] (the applicability of thermodynamical methods in the analysis of phase equlibria in small-volume systems as well as their applicability limits are discussed in [23]). ...
... At the same time, in the analysis of phase equilibria in systems of a small volume, it is necessary to take into account several characteristic features. These peculiarities manifest themselves in significant dependences of mutual solubilities of components and equilibrium volume fractions of coexisting phases on the volume [9][10][11][12][13][14][15][16][17][18][19][20], shape of a nanoparticle [12][13][14]18], thermodynamical characteristics of the surrounding environment [20] and several other factors [15,17,19]. The equilibrium phase compositions of small-volume systems are significantly different from the phase compositions of the same systems in the bulk state and can be modeled using the methods of equilibrium chemical thermodynamics [21] and several other approaches [22] (the applicability of thermodynamical methods in the analysis of phase equlibria in small-volume systems as well as their applicability limits are discussed in [23]). ...
In this paper, we simulate thermodynamically the morphology-dependent phase equilibria in core-shell nanoparticles of a phase-separating solid solution using the example of W-Cr heavy alloy. The morphology of a nanoparticle is described in the framework of the fractal geometry methods. It is shown that there are two
possible heterogeneous states in a nanoparticle while the compositions of phases in both states differ from each other. The dependences of mutual solubilities of components on the temperature are obtained while the behavior of these dependences significantly differs depending on the particular state and the morphology of nanoparticle under consideration. In nanoparticles of a very complicated morphology, the phase separation itself gets suppressed and the nanoparticle remains in the homogeneous state at the temperatures significantly below the macroscopic value of the upper critical dissolution temperature. The demonstrated regularities are explained based on three mechanisms of reducing the free energy of the system and the “competition” between them. In the final section, a method for calculating the equlibrium size distributions and average characteristics of nanoparticle ensembles is described along with a technique of measuring nanoparticle fractal dimensions based on the microscopy data.
... Among the n-type semiconductor compounds used in photovoltaics ( Fig. 1), CdSe, CdTe, GaAs, GaP, c-Fe 2 O 3 , BiVO 4 have the optimal band gap [16]. However, despite the high energy conversion coefficients of CdTe [2], the main disadvantages of cadmium halides are the toxicity of cadmium and the small reserves of selenium and tellurium [17]. Compounds containing arsenic and gallium have high conversion rates (from 29.1% to 47.1%) [2], high electron mobility, thermal and radiation resistance [18]. ...
Abstract This review article provides an overview of the properties and methods for synthesis of BiSI and Bi13S18I2 semiconductor compounds in the form of thin films, powders and crystals, as well as their application in photovoltaic and photoelectrochemical devices. Over the past decade, the results of extensive and versatile research on the structure, properties, functionality and potential applications of bismuth-containing semiconductor materials have accumulated. Bismuth halides and chalcohalides are a developing class of materials that have a small band gap, high chemical stability, effective absorbing properties when absorbing light radiation, which causes the registration of high quantum efficiency values and the possibility of their use in photoelectrochemical processes and photovoltaic solid-state elements. This review presents the results of recent developments and basic approaches aimed at obtaining various multicomponent compounds based on bismuth and improving photoelectrochemical properties. Various structures which demonstrate the importance of thin films based on bismuth compounds are also described. The key problems related to the synthesis and development of these materials is presented. This review will provide a deeper understanding and determine the preferred direction for the synthesis of bismuth-containing thin films for energy and environmental applications.
... The permittivity and permeability of the used semiconductor liquid selenium-tellurium alloy are 10 and 27, respectively. 31,32 The study analyzes the performance of the realized metasurface under two cases: (i) changing the concentration of the materials to form eight different semiconductor alloys of Te 1−x − Se x for 0 ≤ x ≤ 0.7 for fixed temperature; (ii) varying the operating thermal condition of each formed alloy of Te 1−x − Se x for 0 ≤ x ≤ 0.7 in the range of 400 to 700 • C (steps size of 100 • C). The characterization for the aforementioned 32 case studies (combination of both "x" and temperature) is done by analyzing the two-port S-parameters of the structure in the frequency range of 20-30 GHz. ...
Metasurface tuning is performed using different ways for a wide range of applications. This study presents the design of a thermally‐tuned all‐dielectric reconfigurable metasurface. A microfluidic channel, filled with different concentrations of tellurium–selenium (Te‐Se) alloy, is added on the top of the elliptical dielectric resonator (EDR) unit cell of the considered metasurface. The electrical properties of used semiconductor alloy are varied in the range of 400 to 700°C (steps size of 100°C). The impact of thermal tuning on the reflection and transmission characteristics of the designed metasurface is analyzed in the frequency range of 20–30 GHz using COMSOL Multiphysics. Obtained results demonstrated that the realized metasurface exhibits reconfigurable behavior in terms of variations in the reflection and transmission characteristics with a change in either temperature or concentrations of selenium and tellurium. The wider bands with high reflection and low transmission frequency bands are obtained with lower concentrations of selenium and tellurium for all operating temperatures. This article propose the numerical design and analysis of a new reconfigurable metasurface based on a microfluidic tunnels filled with tellurium ‐ selenium (Te‐Se) alloy with thermal properties depending on the alloy composition.
... To clarify the temperature for melting 2D Te with a thickness of 50 nm, we conducted the differential function of the deflection curves; the results are shown in Figure S2 and the exact values are given in Table S1. The melting temperature of 50 nm thick 2D Te is approximately 210 • C, which is significantly lower than that of bulk Te (449.5 • C) [30]. Therefore, we estimated that the melting of 2D Te began at approximately 150 • C, but the difference in melting rate appeared as a gradient change in inclination (nonlinearity) and the decline of deflection curves in the 80 nm and 50 nm samples, respectively. ...
Thermal properties, such as thermal conductivity, heat capacity, and melting temperature, influence the efficiency and stability of two-dimensional (2D) material applications. However, existing studies on thermal characteristics—except for thermal conductivity—are insufficient for 2D materials. Here, we investigated the melting temperature of 2D tellurium (2D Te) using the nano-thermal analysis technique and found anomalous behavior that occurs before the melting temperature is reached. The theoretical calculations present surface pre-melting in 2D Te and Raman scattering measurements suggest that defects in 2D Te accelerate surface pre-melting. Understanding the pre-melting surface characteristics of 2D Te will provide valuable information for practical applications.
Bacteria invade the host's immune system, thereby inducing serious infections. Current treatments for bacterial infections mostly rely on single modalities, which cannot completely inhibit bacteria. This study evaluates the therapeutic potential of SeTe–Ag NPs, designed with excellent photo responsiveness, with a particular focus on their dual-action antibacterial effect and wound healing properties. SeTe–Ag NPs exhibited promising synergistic antibacterial effects due to their superior photothermal and photodynamic properties. The investigation records substantial zones of inhibition of bacteria, demonstrating potent antibacterial effect. Furthermore, upon the irradiation of near-infrared (NIR) light, SeTe–Ag NPs exhibit remarkable antibiofilm and wound-healing capabilities. Overall, this study shows the applications of NIR-active SeTe–Ag NPs, which serve as a versatile platform for biomedical applications.
In this work, we used a hydrothermal route to synthesize tellurium selenide-gadolinium tungsten oxide material for supercapacitor application. Structural characterization by X-ray diffraction (XRD) revealed that the composite material consists of phases from the starting materials (i.e. Gd2(WO4)3 and Te0.39Se0.61). The composite material was amorphous up to annealing temperature of 700 °C but became crystalline at and beyond 800 °C. Energy dispersive spectroscopy (EDS) results confirmed that all the elements in Gd2(WO4)3 and Se0.61Te0.39 were present except selenium that was not detected in the composite material due to the possibility of overlap between rare earth elements (REE) with selenium. The band gap energy determined for Gd2(WO4)3 is 3.28 eV and after the incorporation of Te0.31Se0.61, it slightly increased to 3.39 eV for Gd2(WO4)3/Te0.39Se0.61. The electrochemical properties of all the materials indicated a quasi-reversible system and the current response was increasing with increasing scan rates indicating battery-type electrodes. The specific capacity obtained from GCD at a current density of 1.2 A g⁻¹ were 64.3, 17.3 and 23.8 C g⁻¹ for Gd2(WO4)3, Te0.39Se0.61 and Gd2(WO4)3/Te0.39Se0.61, respectively. Gd2(WO4)3 showed superior electrochemical performance compared to the composite however, the composite showed more pseudocapacitive nature.
Antimony sulfide (Sb2S3) is a promising photovoltaic material because of its high absorption coefficient, green and earth‐abundant constituents and suitable bandgap. Sb2S3 planar solar cells from evaporation method without hole‐transport layer suffer from sulfur vacancy (VS) and high back contact barrier. The same group anion exchange method demonstrates efficient solution to fill VS and suppress back contact barrier. However, the same group Te exchange with sulfur treatment has to implement at high temperature, which degrades Sb2S3 film quality. Herein, we developed a confined‐space selenium‐assisted tellurization (c‐SeTe) post‐treatment strategy to overcome above challenges. Material characterizations made certain that most tellurium distributed at the back and there was weak signal in bulk. Further physical characterizations unfolded c‐SeTe role in device performance. The back Se and Te alloying could suppress the back contact barrier to improve the extraction efficiency. And Se and Te codoping in bulk helped to passivate the interface and bulk defects so as to improve the CdS/Sb2S3 heterojunction quality and enhance the long‐wavelength photon quantum yield. Finally, a champion power conversion efficiency (PCE) of 4.95% was obtained, net 0.5% higher than control one. The robust treatment method is expected to promote the fast development of antimony chalcogenide solar cells. This article is protected by copyright. All rights reserved.
