Sn Atoms Research Articles

Optically compatible infrared camouflage performance of ITO ink.

With the rapid development of military reconnaissance technology, reconnaissance devices have been equipped with wideband reconnaissance ability, which imposes increased requirements on camouflage. Developing multiband camouflage materials with good compatibility has become increasingly important. Indium tin oxide (ITO), a transparent conductive oxide with good comprehensive photoelectric properties, exhibits different absorption, reflectivity, and transmission characteristics in different bands of electromagnetic waves. Therefore, ITO might be able to solve broadband and multiband camouflage problems effectively. In this paper, ITO is expressed as In32-xSnxO48. The energy band structure, optical properties, and infrared absorption spectra at different doping ratios of Sn (x = 0, 1, 2, 3) were obtained on the basis of first principle theory, and the camouflage mechanism of ITO in different electromagnetic wavebands was explored. Results demonstrated that when x = 3, specifically, when the doping ratio of Sn atoms was 9.375%, ITO had high transmission in the visible light band and infrared band reflectivity and can realize optically compatible infrared camouflage. In accordance with calculation results, ITO nanodispersion liquid (x = 3) was mixed with green camouflage coating added with some additives to prepare green ITO camouflage ink for silkscreen printing. The ink formed a camouflage protective ink coating after it was coated onto the surface of fabric through silkscreen printing. Results showed that the emissivity of the ITO ink coating decreased by more than 0.13 when its solid content reached 20%, and its camouflage performance in the visible light band was barely affected. The results of this research can guide the application of ITO materials in the field of camouflage.

Ligand-free supermolecules: [Pd2@Ge18]4- and [Pd2@Sn18]4- as multiple-bonded Zintl-ion clusters based on Pd@Ge9 and Pd@Sn9 assembled units.

Understanding intercluster bonding interactions is important in the rational synthesis of building blocks for molecular materials. Such characteristics have been developed for coinage metal clusters resembling single-, double-, and triple-bonded species, coined as supermolecules. Herein, we extend such an approach for understanding main-group clusters, thus evaluating [Pd2@E18]4- clusters (E = Ge, Sn) involving the fusion of parent spherical aromatic [Pd@E12]2- building units. Our results indicate intercluster bonding provided by contribution from 2P and 1G shells centered at each building motif, leading to an overall bond order of 2.70 and 2.31 for [Pd2@Ge18]4- and [Pd2@Sn18]4-, respectively. In addition, 119Sn-NMR patterns were evaluated to complement the experimental characterization of a single peak owing to the insolution fluxional behavior of [Pd2@Sn18]4- as three peaks owing to the three sets of unique Sn atoms within the structure. Magnetic response properties revealed that spherical aromatic characteristics from parent [Pd@E12]2- building units are retained in the overall [Pd2@E18]4- oblate cluster as two spherical aromatic units. Hence, the notion of superatomic molecules is extended to Zintl-ion clusters, favoring further rationalization for the fabrication of cluster-assembled solids.

Anharmonicity and weak bonding-driven extraordinary thermoelectric performance in wrinkled SnSe monolayer with low lattice thermal conductivity

SnSe compound (Nature, 2014, 508, 373–377) has become the star in the field of thermoelectric (TE) materials owing to the environmental friendliness, abundant reserves, and excellent performance. In the present work, the electronic structures, thermal and electronic transport, as well as TE properties of a two-dimensional (2D) wrinkled SnSe monolayer are comprehensively investigated in combination with first-principles calculations and Boltzmann transport theory. The SnSe monolayer is an indirect semiconductor with a bandgap of 2.88 eV using Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional. The “multivalley” band structure of SnSe monolayer is not only beneficial for maximizing the power factor, but also leads to low lattice thermal conductivity (κl) (1.37/1.42 W/mK @ 300 K armchair-/zigzag-direction). The further crystal orbital Hamilton population (COHP) analysis shows that the low κl in SnSe monolayer is attributed to weak antibonding state below the Fermi level, which in turn weakens the chemical bonding and leads to the mutual exclusion of Sn and Se atoms. As a consequence, the softening of phonon modes and a significant reduction in the phonon group velocity are discovered for the SnSe monolayer, which is beneficial for strong anharmonicity and significant phonon scatterings. Additionally, the electronic transport properties of the 2D SnSe monolayer are evaluated by taking into account the electron-phonon interactions, and the optimal ZTs of 2.13 (armchair-direction) and 3.01 (zigzag-direction) are achieved for n-type and p-type SnSe monolayer at 900 K, respectively. Our present work can not only provide fundamental understanding of thermal and electronic transport properties of wrinkled SnSe monolayer, but also shed some light on the theoretical design of low dimensional SnSe-layered material in thermoelectric applications.

Peculiarities of interaction between oxygen and solute/vacancy in commercial-type zirconium-based alloys: A first-principles study

Unveiling the interaction between dissolved oxygen and solutes/vacancies during the initial stages of oxide layer formation at microscale is significant for the peculiarities of Zr-based alloys oxidation exposed in PWRs or LWRs. We perform ab-initio calculations of the diluted zirconium-based alloys with dissolved Nb and Sn solutes, vacancy and oxygen atom and discuss the solute-oxygen and vacancy-oxygen binding. Our analysis shows that with increasing content of Nb solutes the attractive interaction between niobium and oxygen becomes much stronger, which results in a decrease in corrosion rate of these alloys at the bre-breakaway regime caused by diffusion of oxygen. An increase in content of Sn in an alloy results in enforce of the repulsive interaction between Sn atom and oxygen, which causing tin-enriched alloys are characterized by an increased corrosion rate. We conclude that the dissolved oxygen can be localized near Nb atom rather than near Sn atom if both impurities are second-nearest neighbors, the dissolved oxygen can capture single vacancy and small vacancy clusters in zirconium matrix. This study provides a deep insight into the details of oxygen segregation in zirconium-based alloys exploited in nuclear-power plants.

Study of natural aging behavior of Al-0.4Mg-1.0Si alloy with the addition of Sn at different solution heat treatment temperatures

In this paper, the combined effect of Sn addition and solution treatment temperature on natural aging (NA) hardness behavior and microstructure of Al-0.4Mg-1.0Si alloy were investigated by hardness test, scanning electron microscope (SEM) and scanning transmission electron microscope (STEM). The evolutions of clusters characterized by three-dimensional atom probe (3DAP) during initials stages of NA are also investigated based on the slow in formation of clusters due to Sn addition. The results shown that a Sn-rich particles with round shape retained in Al matrix after quenching treatment when the added Sn content exceeds it limit solubility, which will reduce the Mg content of the designed alloy. The suppression of NA can be enhanced with the increase in the adding Sn content and solution treatment temperature, which is strongly related to the delay of the segregation of Mg and Si to form clusters due to more trapping vacancies by Sn atoms. The addition of Sn also revealed that the segregation of Si during NA is earlier than that of Mg atoms. The Si-rich clusters are formed preferentially during initial stage of NA, and Mg–Si co-clusters are formed after long period of NA. The Mg/Si ratio and average size of Sn-containing clusters in the 0.04%Sn and 0.1%Sn alloy are obviously higher than that of Sn-free clusters regardless of the 1 day NA or 14 days NA as more Mg atoms are dragged into Sn-containing clusters due to strong interaction between Sn and Mg atoms.

Influence on the mechanical properties and electronic structures of Cu-alloyed Ti5Sn3 compounds from first-principles calculations

First-principles calculations within density functional theory are performed to evaluate the mechanical properties and electronic structures of Cu-alloyed Ti5Sn3 compounds. It was confirmed that the Cu atom prefers to occupy Ti6g site with the lowest site occupation energy. The mechanical properties show that the bulk modulus of Ti5Sn3 can be reduced after Cu alloying. In addition, both the Young's modulus and Poisson's ratio increase and then decrease as the increasing of Cu atoms. The density of states and electron density differences reveal that the replacement of Cu atoms generates new chemical bonds but weakens the p-d orbital hybridization between Ti and Sn atoms, leading to a first increase and then decrease in elastic modulus and hardness.

Understanding the oxidation resistance of zirconium alloy at 1000°C based on the formation of a Zr-Sn intermetallic phase and co-precipitation of Sn and Nb

The oxidation behavior of zirconium alloy in high-temperature steam plays a dominant role in the operation of nuclear reactors under accident conditions. The present work investigated the effect of Sn on the oxidation behavior of zirconium alloys in high-temperature steam at 1000 °C. The results of scanning electron microscopy (SEM), metallographic microscopy and synchrotron X-ray diffraction (S-XRD) analyses show that there are three layers in the oxidized sample, including prior β-Zr, α-Zr(O) and ZrO2. High resolution analyses conducted in these layers by transmission electron microscopy (TEM) show that Sn atoms segregate around the oxide-metal (O-M interface and Zr-Sn intermetallic precipitates only present in the oxide film. Clear atomic arrangements of Zr5Sn3 were obtained by TEM, resulting in accurate identification of the Zr-Sn intermetallic phase. Also, TEM energy dispersive spectroscopy (EDS) maps show that Zr-Sn particles invariably accompany the segregation or precipitation of Nb. However, no clear precipitation sequence was observed, which suggests that a co-precipitation mechanism of Sn and Nb is in operation. As oxidation proceeds, nanovoids next to the Zr-Sn intermetallic particles were observed accompanied by local areas deficient in oxygen, identified as ZrO. Combining the interdiffusion trend obtained by Density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations, a mechanism for the transformation from the Zr-Sn intermetallic precipitates to nanovoids was proposed. This proposed mechanism may shed new light into the role of Sn in the oxidation resistance of zirconium alloy under LOCA conditions.

Engineering the electromagnetic response and thermoelectric performance of half-functionalized stanene with [formula omitted], [formula omitted], [formula omitted], [formula omitted] and [formula omitted

We report on, for the first time, a combined density functional theory and Boltzmann-semiclassical calculations of two-dimensional stanene half-passivated with X=H,F,Cl,Br and I The thermodynamical stability is examined through the comparison of the formation energy as well as the analysis of the phonon dispersion spectrum indicating a possible experimental fabrication of these stanene derivatives. Interestingly, using generalized gradient approximation (GGA), the obtained results show that half-iodination and half-hydrogenation induce a half metallic ferromagnetic character and the magnetic moment on the unsaturated Sn atoms are 0.41μB and 0.38μB for SnSn–H and SnSn–I respectively, whereas half-decoration with fluorine, chlorine and bromine adsorbates, characterized with high electronegativity, gives rise to antiferromagnetic metallic systems. Except SnSn–I, the critical temperatures of the stanene derivatives are above room temperature. These results suggest that magnetism of stanene can be tuned by different passivation atoms. The transport properties, which result in a thermoelectric figure of merit (ZT), are very sensitive to the doping type however, less affected by the temperature variation. The highest ZT value of 0.99 is recorded for the SnSn–H conformer, while it decreases with the increase of the electronegativity. For the four compounds, the maximum figure of merit and seebeck coefficients are located at n-type doping, suggesting that these materials can be strong candidates among n-type materials for thermoelectric applications in high-temperature regions. Our findings demonstrate that half passivation with X-atoms is a feasible method to tune the properties of stanene for spin injection applications and thermoelectric cooling industry.

Density Functional Theory Study of Structural Evolution, Relative Stability, and Electronic Properties of SnnAln (n = 2–12) Clusters

The ground‐state structure, average binding energy (Eb), fragmentation energies (ΔE), second‐order difference energy (Δ2E), gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital (HOMO‐LUMO), vertical ionization potential (VIP), vertical electron affinity (VEA), and charge transfer of SnnAln (n = 2–12) clusters are evaluated by density functional theory (DFT). With an increase in the cluster size n, Al atoms aggregate in the geometric center of the cluster, and Sn atoms encapsulate Al atoms in the periphery of the cluster. The variation of ΔE, Δ2E, the HOMO‐LUMO gap, VIP, and VEA of the SnnAln clusters follows similar trends, with certain odd–even oscillations. However, beyond the cluster size n ≥ 9, the HOMO‐LUMO gap decreases significantly, and the VIP and VEA fluctuate significantly, indicating a deterioration of the relative stability of the cluster. Charge transfer proceeds from the Sn atom to the Al atom. This study provides an analysis of the interaction between Sn and Al at the atomic level and explains the segregation phenomenon during the preparation of tin‐aluminum alloys.

Magnetization and exchange-bias effect in powders of the Heusler Ni2MnSn-based alloys

Experimentalinvestigation of properties of powders of the Heusler Ni2MnSn-based alloys revealed the extreme suppression of both, the magnetization and the exchange-bias and exchange spring effects in powders of the alloys. Furthermore, the structural transformation between austenite and martensite phases of the alloys is hindered in the powders, hysteresis curves do not exhibit saturation and observed cluster-glass behavior of the powders at low temperature is almost independent on magnetic field and on composition of the alloys. A complex conjunction of exchange-bias effect and frozen magnetization contribution has been revealed in the case of the powders. All the mentioned phenomena are strongly dependent on the size and the shape of particles of the powders prepared either in an agate mortar or in a ball mill. Temperature treatment of the powders and the compressed pellets at temperature 1173 K under argon led to a recovery of the applicable properties that are characteristic for the bulk alloys. Results of the earlier quantum mechanical calculations of effects of different arrangement of Mn and Sn atoms in crystal structure of the alloys have been used to discuss the observed properties of the powders and to assess a formation of clusters in magneto-crystalline structure of the alloys.

Sn-doped n-type GaN layer with high electron density of 1020 cm−3 grown by halide vapor phase epitaxy

A Sn-doped n-type GaN layer with a high electron density of 2 × 1020 cm−3 and a low resistivity of 8.7 × 10−4 Ω∙cm was grown by halide vapor phase epitaxy (HVPE). Sn doping was performed through the reaction between Sn metal and HCl gas. The Sn concentration markedly increased with decreasing growth temperature and the activation energy of Sn desorption from the GaN surface was found to be 4.1 eV. Smooth surfaces were obtained by introducing the Sn precursor even though the samples were grown at a low temperature of 905 °C, suggesting that Sn atoms act as surfactants and promote the migration of Ga adatoms. Almost all the Sn atoms act as donors in GaN below the Sn concentration of 2 × 1020 cm−3. These results indicate that using the Sn donor is promising for fabricating low-resistivity n-type GaN substrates by HVPE.

Synthesis, structural characterization, and DNA binding/cleavage studies of diorganotin(IV) carboxylates and their complexes with 1,10-phenanthroline: X-ray structures of [Me8Sn4(p-FC6H4CO2)4O2], [Bu2Sn(p-NO2C6H4CO2)2.phen], and DFT studies

The present study is focused on the mode of DNA-interactions with diorganotin(IV) carboxylates and their 1,10-phenanthroline (phen) complexes, and revealed that the planarity and extended π system of phen may increase the probability of DNA intercalation. Diorganotin(IV) derivatives of p-fluoro-/p-hydroxy-/p-nitro benzoic acid, viz. Bu2Sn(p-XC6H4CO2)2: X = F (1), OH (2), NO2 (3), Oct2Sn(p-NO2C6H4CO2)2 (4), and Me8Sn4(p-FC6H4CO2)4O2 (5), and their complexes with phen viz. Bu2Sn(p-XC6H4CO2)2.phen: X = F (6), OH (7), NO2 (8), Oct2Sn(p-NO2C6H4CO2)2.phen (9), and Me2Sn(p-FC6H4CO2)2.phen (10) have been synthesized and characterized by using various techniques including single crystal X-ray diffraction studies, nuclear magnetic resonance (1H, 13C, and 119Sn NMR), electrospray ionization mass spectrometry (ESI-MS), infrared (FT-IR), and elemental analysis. Based on crystal data, complexes (5) and (8) have a P-1 space group with a triclinic crystal system. In the octahedral geometry of complex (5), Sn atom has a tetranuclear Sn4O2 core, whereas complex (8) has a pentagonal bipyramidal geometry around Sn atom. The LanL2Z basis set has been employed for optimized gas-phase geometries, and the calculated ∠C-Sn-C bond angles agree with those obtained from NMR/X-ray studies. UV-visible, fluorescence and circular dichroism (CD) titrations showed interaction with Calf Thymus DNA (CT-DNA), and Kb and KSV values in the order of 103–105 M−1 indicate intercalation within the base pairs or in minor groove. Further, gel electrophoreses studies indicate that all of the complexes have efficiently cleaved plasmid pBR322 DNA into three bands; supercoiled, nicked/circular along with linear structure. The intriguing biophysical results suggest that these complexes may have anticancer potential.

An ab initio study of vertical heterostructures formed by CdO and SnC monolayers

Assembling two dimensional (2D) materials in vertical heterostructures is one of the main techniques for tuning electronic and optical properties. In most cases, known as van der Waals heterostructures (vdWHs), the interlayer distances are larger than typical covalent bond lengths resulting in weak interlayer interactions. It has been shown that reducing the distance between the layers can significantly alter the properties of separated layers, which is not so noticeable in vdWHs and thus creates a new platform for controlling the physical properties of 2D materials. Motivated by enhanced properties of 2D vertical heterostructures, employing ab-initio calculations based on density functional theory we examined CdO/SnC systems in four different configurations. Our results reveal that in spite of thermodynamic and mechanical stabilities of all considered structures, according to the calculated phonon frequencies, only the structure formed by placing the Sn atom on the O atom and the C atom on the Cd atom is dynamically stable at zero temperature. This structure has an interlayer distance of 2.52 Å which is smaller than the interlayer distance in typical vdWHs. We investigated the electronic and optical properties of this dynamically stable structure utilizing GW approximation and solving Bethe–Salpeter equation. Unlike the monolayer CdO which possesses a single optical absorption peak close to the red light energy, the considered CdO/SnC structure has an optical band gap of 1.14 eV, and it can absorb 13% of incident light in the blue light region.

Effect of shear strain on the electronic and optical properties of Al-doped stanane.

The quasi-metallic properties of stanene limit its prospects in optoelectronic devices. Based on first-principles calculations, a systematic study is conducted on the tuning effects of surface hydrogenation and Al atom doping on the electronic and optical properties of stanene. Surface hydrogenation serves as an ideal way to open the forbidden band of stanene, and Al atom doping further increases hydrogenated stanene (stanane) band gap to 0.460eV. Deformation has a minor impact on the stability of the stanane-Al structure, while shear strain can effectively modulate the band gap engineering of the doped system, reducing the band gap value from 0.460 to 0.170eV. Deformation induces a redshift in the absorption peak and reflectance, also slowing down the rate of decrease in the absorption coefficient, and enhancing the peak value of light reflectance, which is positively correlated with the degree of shear strain. These findings hold promise for expanding the potential application of monolayer stanane in semiconductor devices. All calculations are performed using CASTEP module in Materials Studio based on the density functional theory (DFT). The Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA) is employed to describe the exchange-correlation energy (Perdew et al., Phys Rev Lett 77(18), 1996). We construct models for both stanene and stanane. The original unit cell of stanene has two Sn atoms, while stanane consists of two Sn atoms and two H atoms, and expand them to a 3 × 3 × 1 supercell with a vacuum layer of 20Å in height to prevent interlayer coupling. After convergence testing, the plane-wave cutoff energy is set to 450eV, and the energy convergence threshold is set to 1 × 10-5eV. The maximum residual stress for each atom is set to 0.01eV/Å. Brillouin zone sampling is performed using a 6 × 6 × 1k-point mesh based on the Monkhorst-Pack method (Monkhorst and Pack, Phys Rev B 13(12), 1976). The k-point accuracy of the density of states and optical properties is 9 × 9 × 1. All calculations are performed using the more advanced OTFG ultrasoft pseudopotential, and structural relaxations are performed using supercells to ensure that the model is fully relaxed. We use the HSE06 functional to calculate the energy band structures of stanane-Al deformed to 0%, 4%, and 8%, resulting in band gap values of 1.465eV, 1.368eV, and 1.016eV, respectively. These values are significantly higher than those obtained using the PBE functional (0.460eV, 0.397eV, and 0.170eV). However, the shapes and trends of the band structures obtained from both PBE and HSE06 calculations are similar. Additionally, the calculation time needed by HSE06 is greatly longer than PBE, which exceeds the capabilities of our computer hardware, and cannot support all subsequent calculations. To investigate the influence of deformations on the variation of band gap values and to conserve computational resources, the subsequent calculations in this study use the PBE functional.

High-rate performance of Li–S/Na–S batteries achieved by C/Sn composites with high active Sn atoms

Li–S batteries and Na–S batteries attract wide attention because of high specific capacity, rich resources and environmental friendliness, but poor rate performance limits their development. Single atoms perform as active sites and promote redox reaction process of sulfur, which are benefit for improving rate performance of Li–S batteries and Na–S batteries. However, many researches only focus on transition metal atoms instead of non-transition metal atoms. Sn atoms are introduced on carbon surface to obtain C/Sn composites and electrochemical performance of C/Sn/S composites in Li–S batteries and Na–S batteries is studied in this paper. As for comparison, electrochemical performance of C/S without Sn atom modified is also studied. Results show that C/Sn/S composite electrodes possess higher rate performance than C/S composite electrodes in both Li–S batteries (359 mAh·g−1 at 20C) and Na–S batteries (151 mAh·g−1 at 20C). High-rate performance of C/Sn/S composite electrodes in Li–S batteries is attributed to catalytic abilities of active Sn atoms and high conductivity of carbon. Researches provide references for structure control and application of carbon composites with non-transition metal atom modified.

Degradation behaviors and crystallization of rapidly degradable polylactic acid prepared by melting through coordination complexation reaction

The nondegradability of petroleum-based non-degradable plastics leads to accumulation of a large amount of waste. The waste disposal method seriously pollutes the environment. The development and application of biodegradable polymers are considered as a green solution to the problem of environmental pollution. However, as the market for degradable materials continues to expand, the rate of production largely exceeds the rate of natural degradation, and the waste accumulation problem cannot be effectively addressed. In this study, PLA-modified materials were prepared by a melt blending method with polylactic acid (PLA) as a matrix material and stannous octoate (Sn(Oct)2) as an accelerator to increase the degradation rate of PLA. The Sn atom in Sn(Oct)2 complexed with the ester group of the PLA molecular chain, leading to destruction of the PLA molecular chain. When the content of the accelerator reached 2 phr, the degradation rate of the modified samples in an alkali solution was more than two times higher than that of the pure PLA, and the biodegradation rate was increased by 73.97% compared to the pure PLA. In addition, the crystallization behavior of PLA can be regulated by Sn(Oct)2. The mechanisms of the acceleration of the degradation and effect on the crystallization behavior were investigated.

Nucleation and growth of Cu6Sn5 during the aging process of Cu/Sn interface in electronic packaging-by in-situ TEM

The rapid nucleation of Cu6Sn5 during the soldering process, as well as its growth at the solid-state interface system (Cu/Sn) during chip service, present significant challenges. To study this, we introduced a small amount of Co element into the Cu-Sn system in order to reduce the formation energy of Cu6Sn5. Through transmission electron microscopy, we performed in situ observations of the nucleation and growth of Cu6Sn5 at the Cu/Sn solid phase interface. Our experimental findings confirm that the diffusion of Cu element at the interface plays a dominant role in the nucleation and growth process of Cu6Sn5. During this diffusion process, once the local concentration of Cu surpasses a threshold, Cu6Sn5 begins to nucleate around the Cu-rich region. The driving force behind this phase transition arises from two factors: non-uniformity of atomic flux at grain boundaries leading to stress accumulation, and localized bonding between a pair of valence electrons on Cu and adjacent Sn atoms, resulting in the formation of a shared orbital. Based on the curvature of the nucleation solid interface, three distinct growth modes have been observed: spiral growth, layer-layer growth, and island growth. These variations stem from changes in the dynamic mechanism associated with the morphology coefficient linked to the interface arc length. The nucleation and growth of Cu6Sn5 are governed by anisotropic attachment kinetics, with the growth process transitioning to diffusion-controlled continuous growth.

Narrowband photoluminescence of Tin-Vacancy colour centres inSn-doped chemical vapour deposition diamond microcrystals.

Tin-Vacancy (Sn-V) colour centres in diamond have a spin coherence time in the millisecond range at temperatures of 2 K, so they are promising to be used in diamond-based quantum optical devices. However, the incorporation of large Sn atoms into a dense diamond lattice is a non-trivial problem. The objective of our work is to use microwave plasma-assisted chemical vapour deposition (CVD) to grow Sn-doped diamond with submicron SnO2 particles as a solid-state source of impurity. Well-faceted diamond microcrystals with sizes of afewmicrometres were formed on AlN substrates. The photoluminescence (PL) signal with zero-phonon line (ZPL) peak for Sn-V centre at ≈620 nm was measured at room temperature (RT) and at 7 K. The peak width (full width at half-maximum) was measured to be 1.1-1.7 nm at RT and ≈0.05 nm at 7 K. The observed variations of ZPL shape and position, in particular, narrowing of PL peak at RT and formation of single-line fine structure at low-T, are attributed to strain in the crystallites. The diamond doping with Sn via CVD process offers a new route to from Sn-V colour centre in the bulk of the diamond crystallites. This article is part of the Theo Murphy meeting issue 'Diamond for quantum applications'.

Tin Sulfide Nanoparticles as a p-Type Semiconductor Material: Synthesis and Characterization

In this paper, the synthesis and characterization of tin sulfide as a p-type semiconductor material are reported. The low-cost, straightforward use of the transparent conductive tin sulfide technique of chemical bath deposition. The pH levels (7, 8, 9, and 10) were changed while maintaining a fixed bath temperature to create the tin sulfide nanoparticles. XRD, FTIR, and UV-visible were all used to look at the tin sulfide nanoparticles used in this study and learn about their structure and how they move light. Created via chemical bath deposition at various pH values to examine how pH affects the characteristics of the nanoparticles. Tin sulfide structural analysis and crystalline size are revealed by its X-ray diffraction pattern, and both are shown to be affected by changes in pH. Correspondingly, for pH 7, pH 8, pH 9, and pH 10. Tauc plot was used to determine the SnS nanoparticles' optical bandgap energies. From pH 7 to pH 10, it was noticed that the size of the SnS nanoparticle crystallite decreased. It was shown that the quantum confinement effect makes the band gap energy of SnS nanoparticles go up as the sizes of the crystallites get smaller. FTIR spectra confirm the dominating bond stretching of sulfur (S) and tin (Sn) atoms. The SnS nanoparticles generated with enhanced optical characteristics might be employed as an absorber layer in the development of SnS-based heterojunction solar cells, according to optical characterization, which demonstrates that the direct energy band gap (Eg), which is seen to rise with increasing pH values, is increasing with pH values.

First-principle study of shear deformation effect on Mg adsorption by monolayer SnS2.

In this study, the effects of different shear deformations on the structural stability, electronic structure, and optical properties of a Mg atom adsorption system of S vacancy defect SnS2 are systematically investigated based on density functional theory. It is shown that the presence of an S-vacancy defect makes the band gap of the SnS2 system significantly smaller than that of the perfect SnS2 system, and the SnS2 system is changed from a direct band gap semiconductor to an indirect band gap semiconductor. The optimal adsorption position of a Mg atom on the S-vacancy SnS2 system is above the S atom where the adsorption energy is the largest and the system is the most stable. The density of states of the adsorption system is predominantly contributed by the S-3p and Sn-5s orbital electrons. The imposition of shear deformation leads to the introduction of certain impurity energy levels in the adsorption system, and the forbidden bandwidth near the Fermi energy level decreases. As compared to the intrinsic SnS2, the absorption and reflection peaks of adsorption systems under different shear deformation are red-shifted and appear in the ultraviolet region. This improves the utilization of the adsorption system for ultraviolet light to a great extent. The model calculations in this paper are performed using the CASTEP module of the Material Studio (MS) software based on the first principles of Density Functional Theory (DFT) (Wei et al. in Physica B 545:99-106, 2018) for plane wave artifacts. Geometrical optimization and computational procedures are used to calculate the exchange-correlation energy using the Perdew-Burke-Ernzerhof (PBE) generalized function (Perdew et al. in Phys Rev B Condens Matter 48:4978, 1993) of the generalized gradient approximation (GGA). The Monkhorst-Pack method (Monkhorst and Pack in Phys Rev B 13:5188-5192, 1976) was used to rationalize the sampling of the highly symmetric k-points in the Brillouin zone. The grid of k-points is set to be 6 × 6 × 1. The plane-wave truncation energy is set to be 400eV. The energy convergence criterion is 1.0 × 10-5eV. The residual stress of all atoms is 0.01eV/Å. A vacuum layer with a thickness of 15Å is set up in the z-direction, which ensures that the interactions of the system along the z-axis between the top and the bottom layers can be ignored during the whole simulation process. We construct a 3 × 3 × 1 SnS2 system containing 27 atoms as the computational model. The intrinsic SnS2 contains 9 Sn atoms and 18 S atoms.