Sb Doping Research Articles

Correlation between some physical properties of pure and Sb doped Cu2SnS3 thin films under the effect of sulfur amount for solar cell application

Adjusting of sulfur content and amount of doping in Cu2SnS3 (CTS), as absorber layer for solar cell, is a promising approach to fabricate thin film solar cells with high performance. In this work, the effect of different amounts of sulfur in the sulfurization process and the percentage of Sb doping in the films were studied. The physical properties of un-doped and doped CTS thin films were investigated. The pure and doped CTS thin films showed a monoclinic structure, with a larger grain size under the influence of Sb doping. XPS analysis demonstrated that Cu, Sn, S, and Sb oxidation states were +1, +4, −2, and +3, respectively. The Sb-doped sample for 25 min (25Sb) has a higher Cu+1/Cu+2 ratio than other samples and no satellite peak of Sn+2 was observed as compared to other levels of doping samples. This concluded that the Cu species in the 25Sb film experienced a more Cu-rich chemical environment. Both PL and UV–Vis spectroscopy were used to obtain the optical properties. Hall Effect was applied to measure the electrical properties of un-doped and doped CTS films. The pure and Sb-doped CTS solar cells were fabricated by optimization of Sb doping time and sulfur amount. The conversion efficiency of the prepared solar cell was 2.13% when fabricated with CTS layer that treated with 25 min of Sb doping and 100 mg of sulfur, whereas the efficiency of the un-doped CTS solar cell at the same sulfur amount was just 0.615%.

High performance GeTe thermoelectrics enabled by lattice strain construction

Numerous intrinsic Ge vacancies in thermoelectric GeTe not only lead to overhigh carrier concentration but also seriously deteriorate carrier mobility, which shackles its thermoelectric performance. The efficient strategy and the related underlying mechanism in suppressing intrinsic Ge vacancy, however, are rarely researched yet. Herein, we demonstrated that lattice strain could be employed to regulate the defects concentration and then optimize electrical transport performance. Theoretically, the calculated results showed that lattice strain could efficiently raise the formation energy of Ge vacancies, weakening the carrier scattering and improving the carrier mobility. Calculated band structure revealed that Sb doping and Ge vacancy introduction could promote band convergence and thus efficiently decouple the electrical transport parameters. Experimentally, lattice strain was constructed through high-energy ball milling combined with spark plasma sintering to reduce the concentration of Ge vacancy and relaxation time of phonons, leading to high carrier mobility and low lattice thermal conductivity. Additionally, we carefully modulated the nominal content of Ge, and then a high ZT of 2.0 at 723 K in Ge0.90Sb0.08Te alloy was obtained. This work highlights that the lattice strain can be utilized to simultaneously optimize thermal and electrical transport properties.

Polar and Non-Polar Zn1−xMgxO:Sb Grown by MBE

The article presents a systematic study of Sb-doped Zn1-xMgxO layers, with various concentrations of Mg, that were successfully grown by plasma-assisted MBE on polar a- and c-oriented and non-polar r-oriented sapphire substrates. X-ray diffraction confirmed the polar c-orientation of alloys grown on c-and a-oriented sapphire and non-polar structures grown on r-oriented substrates. A uniform depth distribution of the Sb dopant at level of 2 × 1020 cm-3 was determined by SIMS measurements. Raman spectroscopy revealed the presence of Sb-related modes in all samples. It also showed that Mg alloying reduces the compressive strain associated with Sb doping in ZnO. XPS analysis indicates that the chemical state of Sb atoms in ZnMgO is 3+, suggesting a substitutional position of SbZn, probably associated with two VZn vacancies. Luminescence and transmission spectra were measured to determine the band gaps of the Zn1-xMgxO layers. The band gap energies extracted from the transmittance measurements differ slightly for the a, c, and r substrate orientations, and the differences increase with increasing Mg content, despite identical growth conditions. The differences between the energy gaps, determined from transmission and PL peaks, are closely correlated with the Stokes shift and increase with the Mg content in the analyzed series of ZnMgO layers.

Detection of ammonia gas at room temperature through Sb doped SnO2 thin films: Improvement in sensing performance of SnO2

This paper presents the effects of Sb doping on the gas-sensing properties of SnO2 thin films prepared through a nebulizer-assisted spray pyrolysis technique. An improvement in the inherent characteristics of the transparent conducting oxide after 0 to 5 wt% Sb doping is reported. The deposited films were used to sense the presence of 50 to 250 ppm of ammonia at room temperature. Various analytical techniques were used to analyze the properties of the Sb-doped SnO2 films. X-ray diffraction spectra revealed the tetragonal structure of crystallites, and the maximum crystallite size was observed in the 2-wt%-Sb-doped SnO2 film. The morphological images showed spherical grains in pristine SnO2 films and their transformation to a trigonal shape after Sb doping; particularly, a large grain size was observed at 2 wt% doping. PL studies of the materials revealed that a large number of oxygen vacancies exist in the 2-wt%-Sb-doped SnO2 thin film. The transmittance of the films remained at approximately 75%, and the band gap varied from 3.94 to 4.01 eV as the doping concentration varied from 1 to 5%. A high response of 138% was observed for 250 ppm of ammonia in the case of the 2-wt%-Sb-doped SnO2 film, with a 42 s response time and a 11 s recovery time. Thus, the 2-wt%-Sb-doped SnO2 thin film has suitable characteristics for application as an efficient gas sensor to detect ammonia.

Thinnest npn homojunction for inspired photoelectrochemical water splitting

Tin monosulfide semiconductors have great potential for a wide range of applications related to solar energy conversion, however, the photoelectrochemical water splitting performance and stability of tin monosulfide are still inferior. To bridge the gap, effective strategies should be developed to optimize tin monosulfide semiconductors. Here, we report for the first time the thinnest sandwiched SnS n-p-n homojunction regulated by Sb doping and Sn vacancies (npn-SnS). Experimental observations and density functional theory calculations reveal that Sb doping and Sn vacancies form a bidirectional built-in electric field that can enhance the separation and transport efficiency of carriers. Due to the interaction between Sb and S, the thickness of npn-SnS is only 1.69 nm, and defect-related recombination is suppressed after Sb doping. As a result, the photocurrent density of the ultrathin npn-SnS photocathode is 3.3 mA cm−2, which is 4 times higher than that of p-SnS (containing Sn vacancies) and surpasses all SnS-based photocathodes reported so far. This work synthesizes the thinnest sandwiched n-p-n homojunction, which can serve as a guide for improving the carrier separation efficiency and stability of other semiconductors.

Evolution of the optical response of the magnetic topological insulators Mn( Bi1−xSbx)2Te4 with Sb content

MnBi$_2$Te$_4$ is a promising representative of intrinsic antiferromagnetic topological insulators, which could enable rare quantum mechanical effects like the quantum anomalous Hall effect. Especially at low temperatures, numerous studies have been reported, demonstrating the great potential of this compound in the magnetically ordered state below $T_{\mathrm{N}}$. Among recent findings, the alloy compound Mn(Bi$_{1-x}$Sb$_x$)$_2$Te$_4$ has been suggested to be an interesting candidate for the realization of an ideal Weyl semimetal state. By exchanging Bi by Sb, the electronic structure is influenced in terms of a shift of the Fermi energy, and a decrease in the energy gap has been predicted. In this work, we investigate and compare the optical conductivity of Mn(Bi$_{1-x}$Sb$_x$)$_2$Te$_4$ single crystals with various Sb doping levels $x$ by infrared reflectivity measurements. We observe a big impact of the Sb content on the low-energy excitations characterizing the metallic state of our samples. Different $x$=0.26 crystals show significant differences in their optical response and also a strong position dependence. The findings are compared to the recently reported optical conductivity spectrum of the pure compound MnBi$_2$Te$_4$.

Impact of Sb-insertion on structural, optical, and dielectric characteristics of the PbI2 thin film

Antimony (Sb) has been widely used as an additive in solar cells for enhanced performance. We described a simple, affordable, solution-processed approach for producing pure and antimony (Sb3+)-doped lead iodide (PbI2) thin films with varying doping ratios (0.5, 1.0, 2.0, and 3.0%). Structural, optical, and dielectric properties were investigated using XRD and UV–Vis spectroscopy. The XRD spectra illustrated that the synthesized PbI2 thin films have a preferred orientation along the c-axis (001) with a hexagonal structure. The crystalline sizes of PbI2 increased by increasing the Sb-doping concentration up to 1%, then decreased with 2% and 3% Sb-doping. In the visible and NIR regions, the optical transparency of the grown films were in between 70 and 80%. The optical band gap changes inversely with the crystalline sizes; it decreases with 0.5% and 1% Sb-doping and increases with further doping. As the energy gap is spanned between 2.39 and 2.27 eV, therefore, Sb: PbI2 films are ideal for use in solar cells. The resulting refractive index values were found to rise as the Sb doping concentration increased. Sb-doping decreases optical conductivity and dielectric constant.

A High-Rate, Durable Cathode for Sodium-Ion Batteries: Sb-Doped O3-Type Ni/Mn-Based Layered Oxides.

O3-Type layered oxides are widely studied as cathodes for sodium-ion batteries (SIBs) due to their high theoretical capacities. However, their rate capability and durability are limited by tortuous Na+ diffusion channels and complicated phase evolution during Na+ extraction/insertion. Here we report our findings in unravelling the mechanism for dramatically enhancing the stability and rate capability of O3-NaNi0.5Mn0.5-xSbxO2 (NaNMS) by substitutional Sb doping, which can alter the coordination environment and chemical bonds of the transition metal (TM) ions in the structure, resulting in a more stable structure with wider Na+ transport channels. Furthermore, NaNMS nanoparticles are obtained by surface energy regulation during grain growth. The synergistic effect of Sb doping and nanostructuring greatly reduces the ionic migration energy barrier while increasing the reversibility of the structural evolution during repeated Na+ extraction/insertion. An optimized NaNMS-1 electrode delivers a reversible capacity of 212.3 mAh g-1 at 0.2 C and 74.5 mAh g-1 at 50 C with minimal capacity loss after 100 cycles at a low temperature of -20 °C. Such electrochemical performance is superior to most of the reported layered oxide cathodes used in rechargeable SIBs.

Advanced Concentration Gradient Cathode Material for Next-Generation Electric Vehicles

With the prevalence of electric vehicles (EVs), the use of Li-ion batteries (LIBs) in EVs presents a new set of challenges such as cost, charging behavior, driving range per charge, risk of thermal runaway, and battery life. As the performance of LIBs is largely determined by the cathode material, the development of high-performance LIBs for EVs has focused on increasing the capacity of the cathode by using Ni-rich Li[NixCoyAl1−x−y]O2 (NCA) and Li[NixCoyMn1−x−y]O2 (NCM) cathodes.1 Ni-rich core encapsulated by a shell with concentration gradients (CSG) is the only field-proven strategy that is able to tap the potential capacity of Ni-rich cathodes while providing long cycle life.2 Despite the success of CSG cathodes, concentration gradients in the hydroxide precursor are intrinsically unstable and susceptible to flattening through interdiffusion during lithiation process.3 Furthermore, excessive coarsening during lithiation destroys the aligned microstructure, which undermines the mechanical stability of the cathode against microcrack formation.3 Therefore, CSG cathodes require a narrow processing temperature window; however, this increases their manufacturing cost.Herein, it was demonstrated that the doping of a CSG cathode with an average composition of Li[Ni0.9Co0.5Mn0.5]O2 with 0.5 mol% Sb substantially improved its cycling stability while providing manufacturing flexibility. Sb doping allowed precise tailoring of the cathode microstructure through the retardation of cation migration and the inhibition of coarsening by pinning particle boundaries. The Sb-doped CSG cathode retained ~80% of its initial capacity for 2500 cycles, while the pristine CSG90 cathode showed similar capacitive deterioration over only 1500 cycles. The proposed Sb-doped CSG90 cathode for use in electric vehicles represents an ideal high-energy-density cathode with a composition engineered to maximize capacity; its modified microstructure ensures a long battery life and ease of manufacturing, enabling cost reduction. Reference s : [1] H.-J. Noh, S. Youn, C. S. Yoon, Y.-K. Sun, J. Power Sources, 2013, 233, 121.[2] U.-H. Kim, H.-H. Ryu, J.-H. Kim, R. Mucke, P. Kaghazchi, C. S. Yoon, Y.-K. Sun, Adv. Energy Mater. 2019, 9, 1803902.[3] G.-T. Park, H.-H Ryu, T.-C. Noh, G.-C. Kang, Y.-K. Sun, Mater. Today, 2022, 52, 9.

Linear magnetoresistance in textured Bi1−xSbx ribbons prepared by melt spinning method

Bi1−xSbx alloys with large linear magnetoresistance (LMR) are a promising candidate for magneto-electronic devices. In this work, the highly (00l) textured Bi1−xSbx (0 ≤ x ≤ 0.04) ribbons with nano-sized lamellar grains were prepared by the melt spinning method and their magneto-transport properties were investigated. All the ribbons exhibit obvious LMR features, and the crossover magnetic field (Bc) from quadratic to linear magnetoresistance is remarkably reduced by Sb doping. Compared with the Bc of the x = 0 ribbon (about 1.28 T at 300 K), the Bc values of the Sb doped ribbons are significantly smaller, especially for the Bc of the x = 0.03 ribbon (only about 0.53 T at 300 K). Besides, for the x = 0.03 ribbon, the parameter Φ (MR%(B = 1 T)/Bc) relevant to LMR performance reaches up to 52 at 300 K. Analysis of the LMR reveals that Sb doping makes the LMR mechanism transition from recombination of carriers for x = 0 ribbon to spatial fluctuation of carrier mobility governed LMR for x = 0.03 ribbon. This work is instructive to understand the transport features of textured Bi1−xSbx ribbons.

Enhancement of infrared shielding property of SnO2 using Sb as a dopant

Transparent conducting oxides (TCO) are essential to the operation of advanced energy harvesting and storage devices, as well as display technology. Doped tin oxide (SnO2) exhibits enhanced optical and thermal characteristics in comparison to undoped SnO2. In this article, the cost-effective sol-gel methodology was employed in the synthesis of tin oxide (SnO2) and antimony (Sb) doped tin oxide nanoparticles. According to the XRD analysis, the tetragonal structure was maintained despite the apparent reduction in crystal size as the amount of Sb increased. In the study, the effect that Sb doping has on absorption and reflection in the visible and near-infrared regions was analyzed. The band gap of the nanoparticles was observed to broaden as the concentration of Sb doping was increased from 3.44 eV (ATO-0) to 4.62 eV (ATO-6). The results from UV–vis-NIR spectra demonstrated that the ATO films efficiently reduced the amount of infrared light that passed through them. The results of the heat-insulation test showed that ATO-coated glass outperformed uncoated glass in terms of heat insulation. Because of these characteristics, ATO could be a good replacement material, especially for solar cells and smart windows.

Structural and optical properties of GaAs and InAs for doping Sb under the effect of pressure and temperature: DFT and EPM investigations

We have developed first-principles calculations utilizing the empirical pseudopotential method and density functional theory to examine the basic behaviors of the GaAs and InAs semiconductor compounds for doped Sb. The electronic and optical responses of these compounds were calculated. We examined the impacts of the temperature and pressure with the energy band forbidden and parameters of optical parameters (static dielectric constant) of the considered compounds. The literature hasn’t fully analyzed the electronic and optical characteristics of the compounds with doping Sb under the impact of pressure and temperature for fixed composition (x = 0.5). So, we concentrated on the study of these properties.

Effects of Bi and Sb doping on the thermoelectric performance of n-type quaternary Mg2.18Ge0.1Si0.3Sn0.6 materials

Mg2.18(Si0.3Ge0.1Sn0.6)1-yXy (X ​= ​Bi, Sb; y ​= ​0, 0.02, 0.06) quaternary solid solutions were synthesized via solid state reaction after ball milling followed by hot-pressing. The influences of Bi and Sb doping on its thermoelectric (TE) properties, such as thermal conductivity, Seebeck coefficient, and electrical conductivity were discussed in the temperature range of 300–800 ​K. Our results show that Bi and Sb are effective in n-type doping. The results illustrate that the Seebeck coefficient decreases, whereas electrical conductivity increases with increasing temperature for undoped compositions. However, the electrical conductivity decreases in a metal-like behavior for the doped sample. Additionally, the samples doped with Bi0.02 and Sb0.02 show enhanced TE properties as compared to those doped with Bi0.06 and Sb0.06, respectively. A maximum ZT of 1.28 is achieved in the sample doped with Sb0.02.

Effects of Sb Doping on Electrical Conductivity Properties in Fine-Grain KNN-Based Ferroelectric Ceramics

In this work, the effects of Sb doping on the electrical conductivity of fine-grain 0.9(K0.5Na0.5)(Nb1−xSbx)O3-0.1Bi(Ni2/3Nb1/3)O3 (KNNSx-BNN) ceramics were systemically investigated. It was found that the grain size decreases from ~900 nm (x = 0) to ~340–400 nm (x = 0.06–0.08), and then increases again to ~700 nm (x = 0.10). This is because the solubility limit of Sb doping is about 0.08 in this ceramic, and more Sb doping will facilitate the grain growth as the sintering aids. Impedance and conductivity analyses reveal that the grain resistance and its activation energy show a similar changing tendency with grain size, while grain boundary conductivity steadily increases after Sb doping. In this process, the grain contribution on ceramic conductivity changes with grain size variation, and grain boundary contribution becomes more obvious with increasing doping content. The reduction in grain size, improvement in grain boundary density and doping ions entering into the grain boundary should contribute to the evolution of electrical conductivity properties after Sb doping in KNN-based ferroelectric ceramics.

Enhanced thermoelectric properties of Cu2Se via Sb doping: An experimental and computational study

In this study, Cu2Se1−xSbx (x = 0.000, 0.005, 0.010, and 0.015) thermoelectric materials were synthesised using a solid-state reaction technique. A first-principles calculation indicated that the formation energy of the substitution of antimony (Sb) on the Se site is negative and more stable than those of copper (Cu) sites. Sb doping enhanced the lamellar orientation, decreased the grain size, and created an acceptor impurity level. The electrical resistivity and Seebeck coefficient decreased with increasing Sb doping. A minimum reduction in the thermal conductivity by approximately three times that of the undoped sample was obtained at x = 0.005 with a value of 0.40 W/m K at 523 K. The maximum figure of merit (ZT) was obtained at x = 0.005 with a value of 0.47 at 523 K. These findings indicate that substituting Sb into Se sites is an efficient approach for improving copper selenide (Cu2Se) thermoelectric materials.

Antimony Doping of CsBi3I10 for Tailoring the Film Morphology and Defects toward Efficient Lead-Free Thin-Film Solar Cells

The CsBi3I10 (CBI) semiconductor as a light absorber emerges as a promising alternative to lead-based perovskites owing to its low toxicity, good stability, and satisfying physical properties. However, CBI exhibits an uncontrollable crystallization process, poor film morphology, high defect density, and short carrier lifetime, which lead to inferior optoelectronic properties, limiting its practical application in solar cell devices. Here, the Sb doping strategy is successfully developed for CBI films by a one-step antisolvent-free fabrication method. It is found that Sb incorporation in binary CsBi3–xSbxI10 can modulate the crystallization kinetics and optimize the film quality. As a result, polycrystalline films with high density and few pinholes are obtained to enable the enhancement of light absorbance, reduction of defects, suppression of nonradiative recombination, and increase of surface hydrophobicity. The solar cells based on the CsBi2.7Sb0.3I10 film show a remarkably improved power conversion efficiency of 0.82% compared to that of pristine CBI (0.22%), which is among the highest reported efficiencies for CBI-based thin-film solar cells. Moreover, unencapsulated devices based on Sb-doped CBI exhibit outstanding environmental stability and moisture tolerance. This work not only offers insights into understanding the binary Bi-based materials but also provides a new way to fabricate efficient and stable Bi-based solar cells.

Gas sensors based on Pd-decorated and Sb-doped SnO2 for hydrogen detection

Pd-modified Sb-doped SnO2 nanomaterials were prepared by a simple hydrothermal reaction and reduction method. The as-obtained samples were characterized by X-ray diffraction, scanning electron microscopy, X-ray phosphorescence, and elemental mapping analysis. The extracted results demonstrated even doping of Sb within the SnO2 lattice, and Pd was successfully incorporated on the surface of samples. Compared with the pristine SnO2, 3 mol% Sb doping with 7 wt% Pd decorating exhibited the highest response of 9.7 to 100 ppm H2 at 320 °C and revealed excellent selectivity and cycling stability to hydrogen. The mechanism of the enhanced sensing performance of Pd@Sb-SnO2 can be attributed to the change in the energy band structure by Sb doping, the energy-band bending, and depletion layer generated with the Pd loading. The increased oxygen vacancy caused by the lattice distortion generated by the Sb doping, and the strong metal-support interaction effect between the Pd and SnO2 also plays an important role.

Suppression and Mechanism of Voltage Decay in Sb-Doped Lithium-Rich Layered Oxide Cathode Materials.

Voltage decay during cycling is the major problem for lithium-rich layered oxide cathodes. Here, we designed Sb-doped lithium-rich layered oxides prepared by a coprecipitation-solvent thermal method, aiming to alleviate the voltage decay of lithium-rich layered oxides. The midpoint discharge voltage and specific capacity of Li1.20Ni0.133Co0.133Mn0.633Sb0.01O2 (LLMO-Sb1) demonstrate almost no decaying after 100 cycles at 1 C. Moreover, it exhibits a large rate capacity (215 mAh g-1 at 5 C). The suppressed voltage decay and enhanced cycle performance of Sb-doped material are attributed to the high Sb-O bond energy, which can enhance the stability of the layered structure and suppress the layered-to-spinel phase transition. Moreover, Sb doping improves the rate capacity by reducing the energy barrier of lithium ion diffusion. This work opens a gate to prevent the oxidation of superoxo and peroxo, stabilizing the layered structure by selecting an element with a suitable radius and electronegativity.

Doping-dependent optoelectronic, and magnetic properties of monolayer SnS

Based on the first-principles calculations, we examine the effects of In/Sb/P doping on the structure, electronics, and magnetic properties of monolayer SnS. We have examined that the In-/Sb-/P-doped SnS is energetically more favorable under the S-rich condition due to high formation energies. The doping of In at Sn site keeps the semiconducting nature of monolayer SnS, and the Sb doping turns it to metallic. Interestingly, the In-doping turns the non-magnetic monolayer SnS to the magnetic one with a magnetic moment of 1.00 μB. Additionally, the ferromagnetic behavior is observed at a larger distance confirming the large range ferromagnetism in the In-doped SnS. Importantly, for the In-doped system, a high MAE of 40.91 meV is calculated. Furthermore, the doping P at the S-site in monolayer SnS trun the semiconductor nature to a metallic one. Additional experimental studies into the efficient utilization of these systems in the fields of photo-electronics and magnetic semiconductor devices are very desirable.

Microstructure design via novel thermodynamic route to enhance the thermoelectric performance of GeTe

Defect engineering is the core of thermoelectric study: no thermoelectric material can achieve the best performance without implementing proper defects. Designing the appropriate feature size of defects can promote the trade-off between carrier mobility and lattice thermal conductivity. Taking GeTe as an example, the lattice thermal conductivity is mainly contributed by mid- and long-wavelength heat-carrying phonons, while carrier mean free path is close to point defects. Different from the mainstream strategy of oversaturated precipitation of secondary phases, we propose a novel thermodynamically route to rational design microstructures and enhance the thermoelectric performance of GeTe. Thermodynamically, Zn–Cd co-doping reduces the solubility limit of Zn or Cd in GeTe and promotes the generation of nano and micron scale Zn0.6Cd0.4Te secondary phases, thereby reducing lattice thermal conductivity meanwhile leaving a minimal carrier mobility reduction. The further Sb doping significantly reduces carrier concentration and enhances the density-of-state effective mass, thus improving the Seebeck coefficient. In addition, the formed multiscale microstructures via novel thermodynamic route further restrain the lattice thermal conductivity, leading to a maximum zT of 1.60 at 823 K in Ge0.80Sb0.06Zn0.07Cd0.07Te. This work attest to the efficacy of the rational design of microstructures by novel thermodynamic route toward the high zT in GeTe and other TE materials.