Search Results (23)

This study aims to enhance optoelectronic properties of all-inorganic perovskite photodetectors (PDs) by incorporating a bilayer electron transport layer (ETL). The bilayer ETL composed of SnO₂ and ZnO effectively optimizes energy level alignment at the interface, facilitating efficient electron extraction from the CsPbI₂Br perovskite layer while suppressing shunt pathways. Additionally, it enhances interfacial properties by mitigating defects and minimizing dark current leakage, thereby improving overall device performance. As a result, the bilayer ETL-based PDs exhibit broadband photoresponsivity in 300 to 700 nm with a responsivity of 0.45 A W⁻¹ and a specific detectivity of 9 × 10¹³ Jones, outperforming the single-ETL devices. Additionally, they demonstrate stable cyclic photoresponsivity with fast response times (14 μs for turn-on and 32 μs for turn-off). The bilayer ETL also improves long-term reliability and thermal stability, highlighting its potential for high performance, reliability, and practical applications of all-inorganic perovskite PDs. Full article

We performed the microscopic calculation of $\beta$-decay properties for waiting-point nuclei with neutron-closed magic shells. Allowed Gamow–Teller (GT) and first-forbidden (FF) transitions were simulated using a schematic model (SM) for waiting-point N = $50,82$ isotopes in the framework of a proton–neutron quasiparticle random phase approximation ($pn$-QRPA). The Woods–Saxon (WS) potential basis was used in our calculations. The $pn$-QRPA equations of allowed (GT) and (FF) transitions were utilized in both the particle–hole ($ph$) and particle–particle ($pp$) channels in the SM. We solved the secular equations of the GT and FF transitions for eigenvalues and eigenfunctions of the corresponding Hamiltonians. A spherical shape was assigned to each waiting-point nucleus in all simulations. Significantly, this study marks the first time that $\beta$-decay analysis has been applied to certain nuclei, including ⁸²Ge₅₀, ⁸³As₅₀, ⁸⁴Se₅₀, ⁸⁵Br₅₀ and ⁸⁷Rb₅₀ with $N=50$ isotones, and ¹³²Sn₈₂, ¹³³Sb₈₂, ¹³⁴Te₈₂, ¹³⁵I₈₂ and ¹³⁷Cs₈₂ with $N=82$ isotones. Since there is no prior theoretical research on these nuclei, this work is a unique addition to the field. We compared our results with the previous calculations and measured data, and our calculations agree with the experimental data and the other theoretical results. Full article

This paper presents detailed results regarding the physical behavior of Cs₂SnI_6−xBr_x alloys for their potential use in photovoltaic applications. Numerical computations based on density functional theory (DFT) revealed that Br substitution at I sites significantly influenced the electronic structure of Cs₂SnI₆, resulting in an increase in bandgap values from 1.33 eV to 2.24 eV. Additionally, we analyzed the optical properties, including the absorption coefficient, which exhibited high values in the visible light region, highlighting the material’s excellent light-trapping abilities. Moreover, Cs₂SnI_6−xBr_x compounds were employed as absorber materials in an fluorine-doped tin oxide (FTO) TiO₂/Cs₂SnI₆/P3HT/Ag perovskite solar cell (PSC) to investigate its performance. The simulation process consisted of two interconnected steps: (i) the DFT calculations to derive the material properties and (ii) the SCAPS–1D (one-dimensional (1D) solar cell capacity simulator) simulation to model device performance. To ensure reliability, the SCAPS–1D simulation was calibrated against experimental data. Following this, Cs₂SnI_6−xBr_x compound with various ratios of Br content, ranging from 0 to 6, was investigated to propose an efficient solar cell design. Furthermore, the cell structure was optimized, resulting in a development in the power conversion efficiency (PCE) from 0.47% to 3.07%. Full article

Zero-dimensional tin-based halide perovskites have garnered considerable interest owing to their remarkable optical properties, including broad-band emission, high photoluminescence (PL) efficiency, and low self-absorption. Nevertheless, enhancing the PL efficiency and stability of these materials remains a pressing challenge. In this study, the enhancement of PL and stability in Cs₄SnBr₆ zero-dimensional perovskite was investigated through Ce³⁺ doping. Our experimental results demonstrate that the incorporation of Ce³⁺ can significantly boost the light emission intensity from self-trapped excitons (STEs) in Cs₄SnBr₆, achieving over a 150% increase compared to the undoped sample, with a PL quantum yield of approximately 64.7%. Moreover, the thermal stability of the corresponding doped sample is markedly enhanced. Through comprehensive analyses, including X-ray diffraction, energy-dispersive spectroscopy, time-resolved PL, and temperature-dependent PL measurements, we elucidate that the enhanced light emission is attributed to the distortion of the [SnBr₆]⁴⁻ octahedral structure induced by Ce³⁺ doping, which strengthens electron–phonon coupling and elevates the binding energy of STEs. Full article

In this research, SCAPS-1D simulation software (Version: 3.3.10) was employed to enhance the efficiency of CsSnX₃ (X = Cl, Br, I) all-inorganic perovskite solar cells. By fine-tuning essential parameters like the work function of the conductive glass, the back contact point, defect density, and the thickness of the light absorption layer, we effectively simulated the optimal performance of CsSnX₃ (X = Cl, Br, I) all-inorganic perovskite solar cells under identical conditions. The effects of different X-site elements on the overall performance of the device were also explored. The theoretical photoelectric conversion efficiency of the device gradually increases with the successive substitution of halogen elements (Cl, Br, I), reaching 6.09%, 17.02%, and 26.74%, respectively. This trend is primarily attributed to the increasing size of the halogen atoms, which leads to better light absorption and charge transport properties, with iodine (I) yielding the highest theoretical conversion efficiency. These findings suggest that optimizing the halogen element in CsSnX₃ can significantly enhance device performance, providing valuable theoretical guidance for the development of high-efficiency all-inorganic perovskite solar cells. Full article

The assessment of soil contamination in the vicinity of integrated siderurgical plants is of outmost importance for agroecosystems and human health, and sensitive techniques should be employed for accurate assessment of chemical elements (metals, potential toxic elements, rare earths, radioelements) in soil and further evaluation of potential ecological and safety risk. In this paper a total of 45 major, minor and trace elements (Al, As, Au, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Eu, Fe, Hf, Hg, I, K, La, Mg, Mn, Mo, Na, Nd, Ni, Pb, Rb, Sb, Sc, Sm, Sn, Sr, Ta, Tb, Th, Ti, Tm, U, V, W, Y, Yb, Zn and Zr) were quantified in soils located around a large siderurgical works (Galati, SE Romania) using instrumental neutron activation analysis (INAA) in combination with X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP–MS). The statistical analysis results and vertical distribution patterns for three depths (0–5 cm, 5–20 cm, 20–30 cm) indicate inputs of toxic elements in the sites close to the ironmaking and steelmaking facilities and industrial wastes dumping site. For selected elements, a comparison with historical, legislated and world reported concentration values in soil was performed and depth migration, contamination and toxic risk indices were assessed. The distribution of major, rock forming elements was closer to the Upper Continental Crust (UCC), and to the Dobrogea loess, a finding confirmed by the ternary diagram of the incompatible trace elements Sc, La and Th, as well as by the La to Th rate. At the same time, the La/Th vs. Sc and Th/Sc vs. Zr/Sc bi-plots suggested a felsic origin and a weak recycling of soils’ mineral components. Full article

Metal halide perovskites have attracted considerable attention as novel optoelectronic materials for their excellent optical and electrical properties. Inorganic perovskites (CsPbX₃, X = Cl, Br, I) are now viable alternative candidates for third-generation photovoltaic technology because of their high photoelectric conversion efficiency, high carrier mobility, good defect tolerance, simple preparation method and many other advantages. However, the toxicity of lead is problematic for practical implementation. Thus, the fabrication of lead-free perovskite materials and devices has been actively conducted. In this work, the energy band and photoelectric properties of inorganic perovskites CsBX₃ (B = Pb, Sn, Ge, X = Cl, Br, I) have been investigated with the first principles calculation, and the possible defect energy levels and their formation energies in different components, in particular, have been systematically studied. The advantages and disadvantages of Sn and Ge as replacement elements for Pb have been demonstrated from the perspective of defects. This study provides an important basis for the study of the properties and applications of lead-free perovskites. Full article

The contents of 49 trace elements in sub-bituminous Pernik coals and their waste products from preparation and combustion processes were investigated. The studied coals have trace element contents higher than the respective Clarke values for brown coals and some of them may pose environmental concerns. The elements Li, Rb, Cs, Ba, Sc, Y, La, Ce, Nd, Sm, Eu, Er, Ga, Zr, Sn, V, Nb, Ta, W, F, Cu, Zn, In, Pb, Cr, Co, Ni, and Th in the feed coals have concentrations that exceed twice the Clarke values. Most element contents in bottom ash are enriched compared with those in feed coal. Some of the volatile elements are equal or significantly depleted including Sn, Mo, Sb, F, Bi, Cd, Ge, and Pb. Fly ash has higher contents of Ga, Zr, Hf, Sn, V, Nb, Mo, and F in comparison with bottom ash. Most elements have a significant positive correlation with ash yield, indicating their inorganic association. The mixed wastes (coal slurry, bottom ash, and fly ash) in the disposal pond are slightly depleted of most of the elements studied with the exclusion of Cl, Ba, and Br. The Pernik coals and their waste products are unpromising for the extraction of REY due to their low element contents. Full article

Perovskite thin films directly impact solar cell properties, making defect reduction crucial in perovskite solar cell research. In our study, we used perovskite quantum dots in the anti-solvent to act as nucleation centers in MAPbI3 thin films. These centers had lower nucleation barriers than homogeneous nucleation, improving perovskite crystallinity, reducing defects, and extending carrier lifetime. Fine-tuning the energy band also enhanced carrier transport. The most effective results were obtained using CsPb(Br_0.5 I_0.5)₃ perovskite quantum dots. The resulting device, ITO/SnO₂/MAPbI₃ (300 nm)/spiro-OMeTAD (200 nm)/Ag (100 nm), achieved a 12.88% power conversion efficiency, a 16% increase from the standard element. The modified device maintained approximately 95% of its efficiency over 100 h in a 70% humidity environment. Full article

Hybrid perovskites, materials composed of metals and organic substances in their structure, have emerged as potential materials for the new generation of photovoltaic cells due to a unique combination of optical, excitonic and electrical properties. Inspired by sensitization techniques on TiO₂ substrates (DSSC), CH₃NH₃PbBr₃ and CH₃NH₃PbI₃ perovskites were studied as a light-absorbing layer as well as an electron–hole pair generator. Photovoltaic cells based on per-ovskites have electron and hole transport layers (ETL and HTL, respectively), separated by an ac-tive layer composed of perovskite itself. Major advances subsequently came in the preparation methods of these devices and the development of different architectures, which resulted in an efficiency exceeding 23% in less than 10 years. Problems with stability are the main barrier to the large-scale production of hybrid perovskites. Partially or fully inorganic perovskites appear promising to circumvent the instability problem, among which the black perovskite phase CsPbI₃ (α-CsPbI₃) can be highlighted. In more advanced studies, a partial or total substitution of Pb by Ge, Sn, Sb, Bi, Cu or Ti is proposed to mitigate potential toxicity problems and maintain device efficiency. Full article

In the present study, the structural, mechanical, electronic and optical properties of all-inorganic vacancy-ordered double perovskites A₂Sn_1−xTixY₆ (A = K, Rb, Cs; Y = Cl, Br, I) are explored by density functional theory. The structural and thermodynamic stabilities are confirmed by the tolerance factor and negative formation energy. Moreover, by doping Ti ions into vacancy-ordered double perovskite A₂SnY₆, the effect of Ti doping on the electronic and optical properties was investigated in detail. Then, according to the requirement of practical applications in photovoltaics, the optimal concentration of Ti ions and the most suitable halide element are determined to screen the right compositions. In addition, the mechanical, electronic and optical properties of the selected compositions are discussed, exhibiting the maximum optical absorption both in the visible and ultraviolet energy ranges; thus, the selected compositions can be considered as promising materials for application in solar photovoltaics. The results suggest a great potential of A₂Sn_1−xTi_xY₆ (A = K, Rb, Cs; Y = Cl, Br, I) for further theoretical research as well as experimental research on the photovoltaic performance of stable and toxic-free perovskite solar cells. Full article

Zero-dimensional (0D) tin halide perovskites, characterized by their broadband and adjustable emissions, high photoluminescence quantum yield, and absence of self-absorption, are crucial for the fabrication of high-efficiency optoelectronic devices, such as LEDs, solar cells, and sensors. Despite these attributes, boosting their emission efficiency and stability poses a significant challenge. In this work, Cr³⁺-doped Cs₄SnBr_6−xF_x perovskites were synthesized using a water-assisted wet ball-milling method. The effect of CrF₃ addition on photoluminescence properties of Cs₄SnBr_6−xF_x Perovskites was investigated. We found that Cr³⁺-doped Cs₄SnBr_6−xF_x Perovskites exhibit a broad emission band, a substantial Stokes shift, and an efficient green light emission centered at about 525 nm at ambient temperature. The derived photoluminescence quantum yield amounted to as high as 56.3%. In addition, these Cr³⁺-doped Cs₄SnBr_6−xF_x perovskites outperform their undoped counterparts in terms of thermal stability. Through a comprehensive analysis of photoluminescence measurements, our findings suggested that the elevated photoluminescence quantum yield can be attributed to the enhanced exciton binding energy of self-trapped excitons (STEs) and the suitable electron−phonon coupling resulting from the substantial distortion of [SnBr₆]⁴⁻ octahedra instigated by the addition of CrF₃. Full article

Zero-dimensional (0D) tin halide perovskites feature extraordinary properties, such as broadband emission, high photoluminescence quantum yield, and self-absorption-free characteristics. The innovation of synthesis approaches for high-quality 0D tin halide perovskites has facilitated the flourishing development of perovskite-based optoelectronic devices in recent years. However, discovering an effective strategy to further enhance their emission efficiency remains a considerable challenge. Herein, we report a unique strategy employing rapid heat treatment to attain efficient self-trapped exciton (STE) emission in Cs₄SnBr₆ zero-dimensional perovskite. Compared to the pristine Cs₄SnBr₆, rapid thermal treatment (RTT) at 200 °C for a duration of 120 s results in an augmented STE emission with the photoluminescence (PL) quantum yield rising from an initial 50.1% to a substantial 64.7%. Temperature-dependent PL spectra analysis, Raman spectra, and PL decay traces reveal that the PL improvement is attributed to the appropriate electron–phonon coupling as well as the increased binding energies of STEs induced by the RTT. Our findings open up a new avenue for efficient luminescent 0D tin-halide perovskites toward the development of efficient optoelectronic devices based on 0D perovskites. Full article

Environmental protection laws require effective and green solutions to tackle water and air pollution issues. For this purpose, perovskite photocatalytic materials have proven to be a promising solution. In this study, CsSnBr₃ perovskite, coupled with ZIF-67 and decorated with noble metal Au, was shown to effectively enhance the charge separation and increase the light-absorbing capacity, and thus make the photocatalytic reaction more efficient by surface plasmon resonance. Characterization results from XRD, FTIR, and UV-visible diffuse reflectance spectroscopy indicated that a mixture of cubic and tetragonal crystalline phases was found in the prepared catalyst material. XPS also revealed that in the presence of two oxidation states for tin (Sn), the Au 4f XPS peaks of Au NPs coincided with those retained in colloidal Au particles. Using malachite green as a model compound, organic pollutant photocatalytic degradation tests proved that CsSnBr₃ generated good photocatalytic activity for aromatic pollutant degradation. In this research, the synthesized 4Au-7ZIF-CsSnBr₃ catalyst yielded an MG degradation rate twice as high as the unpromoted CsPbBr₃. Full article

With the global movement toward the consumption of a more sustainable diet that includes a higher proportion of plant-based foods, it is important to determine how such a change could alter the intake of cadmium and other elements, both essential and toxic. In this study, we report on the levels of a wide range of elements in foodstuffs that are both traditional and “new” to the Swedish market. The data were obtained using analytical methods providing very low detection limits and include market basket data for different food groups to provide the general levels in foods consumed in Sweden and to facilitate comparisons among traditional and “new” food items. This dataset could be used to estimate changes in nutritional intake as well as exposure associated with a change in diet. The concentrations of known toxic and essential elements are provided for all the food matrices studied. Moreover, the concentrations of less routinely analyzed elements are available in some matrices. Depending on the food variety, the dataset includes the concentrations of inorganic arsenic and up to 74 elements (Ag, Al, As, Au, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Ge, Hf, Hg, K, Li, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Rb, S, Sb, Sc, Se, Si, Sn, Sr, Ta, Te, Th, Ti, Tl, U, W, V, Y, Zn, Zr, rare Earth elements (REEs) (Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Tm, and Yb), platinum group elements (PGEs) (Ir, Os, Pd, Pr, Pt, Re, Rh, Ru, and Pr), and halogens (Br, Cl, and I)). The main focus (and thus the most detailed information on variation within a given food group) is on foods that are currently the largest contributors to dietary cadmium exposure in Sweden, such as pasta, rice, potato products, and different sorts of bread. Additionally, elemental concentrations in selected food varieties regarded as relatively new or “novel” to the Swedish market are provided, including teff flour, chia seeds, algae products, and gluten-free products. Full article