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Coumarin doped with poly(3-hexylthiophene)/p-Si photodiodes were prepared by the drop-casting technique. The current–voltage characteristics of the prepared diodes with the structure of Al/P3HT:Coumarin/p-Si/Al diodes were investigated under dark and various illumination intensities using both I–V and C–V methods. Using both illuminated DC and transient I–V and C–V measurements, the photocurrents are shown to depend on light intensity with the P3HT:Coumarin ratio influencing photoresponsivity. The photocurrents increase with increasing illumination intensity. C–V measurements show that the capacitance of the diode depends on voltage, frequency and illumination, indicating the existence of a continuous distribution of interface states that can be described in terms of organic-organic polymer blend domains in additional to the well studied metal-semiconductor interface states. The best responses were found to be for the diode having 10% Coumarin weight. These results suggest that the Al-p-Si/P3HT:Coumarin/Al diode can be used as a photosensor. [ABSTRACT FROM AUTHOR]

This study investigates the hot deformation behavior and final microstructure features with and without aluminum (Al) incorporation in magnesium (Mg). To this end, pure Mg and Mg-6Al(wt%) alloy were subjected to high-temperature compression and systematically analyzed the flow stress, activation energies, Zener Hollomon parameters, processing maps, and microstructure evolution, including geometrically necessary dislocations under different g vectors. These all were in an excellent relationship with each other. The microstructure analysis greatly validated the processing map parameters. Amazingly, we have attained an unexplored grain boundary sliding phenomenon under high-strain rate compression in pure Mg. This phenomenon is only reported in high-temperature tensile specimens, especially for those who attained superplasticity. Unfortunately, the mechanism attained at a strain rate (10 s−1) and temperature (573 K), which is referred to as an unstable region. Above the temperatures of 573 K, the Mg lost thermal stability, and an abrupt increase in grain size happened (3–40 µm). The addition of Al restricted the abnormal grain growth at elevated temperatures and retained grain size within < 10 µm. The higher geometrically necessary dislocation density and increase in grain boundary energy are the potential reasons for the thermal stability of Mg-Al alloy. Therefore, incorporating the Al not only enhances the formability of Mg but also provides many different stable zones, thermal stability and increases the power dissipation efficiency. • First time we have observed GBS mechanism in Mg under hot deformation. • The addition of Al increases the hot formability, power dissipation and thermal stability at elevated temperatures. • The transitional effect of viscous glide dislocation to GBS mechanism happened in Mg with increase in strain rate. • Under high strain rate, three different zones were developed, twinned zone, transitional zone and fine grain zone. • Processing maps, activation energies, Z-values and microstructure including GND density were in a great consistency. [ABSTRACT FROM AUTHOR]

Co:ZnO (CZnO) ferromagnetic semiconductor layers are coated on the surface of glass and Si substrates by Magnetron Sputter Deposition Method (MSDM) with variable N 2 /Ar gas flow ratio. N 2 /Ar flow ratio varies from 5 sccm to 20 sccm, keeping the Ar gas flow constant (at 30 sccm). Sample's surface topography-composition, structure and optic properties are characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and ultraviolet–visible (UV/Vis) spectrophotometry. CZnO/p-Si structure exhibits both rectifying and photovoltaic behavior. Kohlrausch decay function is used to model the photocurrent transient curve and the associated relaxation process. The values of the photo charge density ( ρ p h ) and the relaxation time constant ( τ 0 ) are found to be 1.02 × 10 11 Coul/cm −2 and 1.1 × 10 4 s, respectively. These findings suggest that CZnO/p-Si structure can be used in photodetector applications. The photoconductivity of the device can be tuned with the N 2 /Ar flow ratio since the property of CZnO thin films deposited from 3% Co doped ZnO target is dependent on the N 2 and Ar atmosphere. [ABSTRACT FROM AUTHOR]

With the advancement of technology, there has been a growing demand for high-capacity energy storing devices possessing good durability and cost-effective production. Herein, Ce doped cobalt molybdate (CoMoO 4) nanocomposites by microwave combustion is prepared and their structural, morphological, spectroscopical and electrochemical behavior are investigated. The β phase monoclinic structure have been confirmed by XRD analysis. The electrochemical behavior of 5% Ce-CoMoO 4 sample shows a specific capacitance value eight times higher than of its undoped CoMoO 4 sample. Furthermore, a symmetric 5% Ce-CoMoO 4 device displays an energy density of 105.54 Wh kg−1 at 1.7 mA cm−2 current density with 82.06% retention after 5000 continuous charge-discharge cycles. The outcome of the present investigation offers the doping approach enhances the energy-storing ability of cobalt molybdate and become an exceptionally promising candidate in the area of energy storage today. [Display omitted] [ABSTRACT FROM AUTHOR]

Water purification is a critical problem for the development and survival of human society, and now it has become a great challenge for the research community. Therefore, MOFs attracted the great intention owing to the large number of active sites, and tailorable porous composition as a fast-growing branch of coordination chemistry. Moreover, MOF-based photocatalysts have proven to be excellent adsorbents in photocatalysis for wastewater treatment. In current review, we have discussed the various synthesis routes, and historical developments of the MOFs. Additionally, recent developments have been explored in the removal, and degrading hexavalent chromium through MOFs under visible light irradiations. In addition, this review demonstrated the development of sustained and efficient metal-organic materials (MOMs), and their modularity, fine-tuneable, and diverse composition with structural features. In this context, numerous investigations have been explored with their classifications of MOF-based heterostructures including 0D, 1D, 2D, and 3D materials, according to their structural, morphological and nature of the catalyst. Furthermore, we have explored the different parameters to enhance photocatalytic reducing ability of hexavalent chromium (Cr6+). In summary, various challenges and future prospects are explained for further advancements in Cr(VI) reduction through MOFs-based nanocomposites under visible light in aqueous media. [Display omitted] • Recent developments in Cr(VI) reduction over the MOF-based materials are reviewed. • Synthesis routes for MOFs and Cr(VI) reduction mechanism are discussed. • The challenges and opportunities of MOFs for Cr(VI) reduction are provided. [ABSTRACT FROM AUTHOR]

It is the first time that we have systematically proved that the activation energy (Q -value) is the main parameter that controls the dynamic recrystallization during hot deformation, and the reliability of the constitutive analysis is entirely dependent on the Q -value. To this end, the hot deformation behavior of a Mg-Gd-Y-Zn alloy was investigated at the temperatures of range 573 K -723 K under strain rates of range 0.0001–1 s −1 . Subsequently, the Q -value ∼ 331.24 kJ mol −1 was achieved. By considering the two different approaches of eliminating the temperatures and then eliminating the strain rates, the lowest Q-values ∼ 259.75 kJ mol −1 and ∼ 295.80 kJ mol −1 were achieved, respectively. Based on the lowest Q -values, the deduced parameters of temperatures range of 623 K -723 K and strain rates range of 0.0001–0.01 s −1 were evaluated. Interestingly, the numerical simulation exhibited a further lower Q -value ∼ 237.17 kJ mol −1 . The difference in the Q -values revealed that the large strain hardenability is due to the high Q -value, while the low strain hardenability is due to the low Q -value. The deduced parameters were also well-matched with the processing maps and the EBSD analysis. Last but not least, the deduced parameters displayed a high accuracy in predicting the flow stresses. Thus, the new approach is of great significance in analyzing the accurate calculation of Q -value, the correctness of constitutive analysis, and evaluating stress-strain behavior. • A new approach was employed for evaluating the activation energy during the hot deformation behavior of WEZ Mg alloy. • The deduced parameters show the lowest Q -value ∼ 237.17 kJ mol −1 . • The higher the Q -value the lower the DRX , While, the lower the Q -value the higher the DRX. • The processing maps, microstructure, and predictive flow stress were accurate with the Q -value of deduced parameters. [ABSTRACT FROM AUTHOR]

Abstract For the Quaternary Chalcogenides BaCu 2 GeQ 4 (Q = S, Se) optoelectronic, structural and transport properties are explored using accurate all electrons FP–LAPW [full potential linearized augmented plane wave] method. The lattice constants calculated theoretically are established to be in fine agreement with the values that are measured experimentally. It is established that all the titled compounds are direct band gap semiconductors and this energy band gap is situated Γ- Γ symmetry points. At the same time the band gap magnitude decreases during replacement of S by Se. Optical constant dispersion like imaginary and real components of dielectric functions, extinction coefficients, refractive indices, reflectivity's, absorption coefficients, have been also calculated for these compounds. High absorption and the direct band gap characteristics of these compounds in the UV–Visible energy range indicate that these perovskite structures might be used in optoelectronic and optical devices working in the UV–Visible range of the energy spectrum. The calculated birefringence (−0.012 and −0.083) enhances the suitability of BaCu 2 GeSe 4 compared to BaCu 2 GeS 4 usually applied as nonlinear optical materials. The computed transport coefficients exhibit the anisotropic nature of the materials, in agreement with their electronic states. The transport properties show stronger carrier concentrations along the Ge-s, Ba-p and Cu-d orbitals, confirming that these orbitals are principal for the electrical transport features. The values of effective mass of electrons are computed by curvature of the CBM band 124 and 184 for BaCu 2 GeS 4 and BaCu 2 GeSe 4 respectively. Investigating of the thermoelectric power factor shows that BaCu 2 GeS 4 is much better than BaCu 2 GeSe 4 over the entire temperature interval which make it suitable for future technological applications. Graphical abstract Image 1 Highlights • Thermoelectricity of BaCu 2 GeQ 4 (Q = S and Se) compounds is explored. • The energy band gaps are of direct type with the extrema situated at R BZ points. • Plasmon resonances are observed in UV spectral range (6–12 eV). • Thermal conductivity of BaCu 2 GeSe 4 is lower than BaCu 2 GeS 4. [ABSTRACT FROM AUTHOR]

Abstract Using first principles density functional theory (DFT) simulations, the structural, electronic, optical and elastic properties of CaTa 2 O 6 oxide for cubic and orthorhombic phases are studied by highly accurate (FP-LAPW) method within the GGA + U approximation. The calculated lattice parameters are consistent with available experimental data. The electronic band structure calculations have shown that the band gaps in CaTa 2 O 6 are equal to 3.08 eV and 4.40 eV for the cubic and orthorhombic structures, respectively. For both the phases the main optical properties, e.g., absorption coefficient, dielectric constant, energy loss function, reflectivity are calculated and discussed in detail in the spectral range 0–14 eV. Cubic and orthorhombic phases exhibit significantly different optical characteristics. The electronic bonding characters of CaTa 2 O 6 with different symmetries are explored via charge density distribution mapping. Strong covalent bonding character dominates in both the phases of CaTa 2 O 6. Elastic properties of CaTa 2 O 6 for cubic and orthorhombic phases are also investigated. The stress strain method is used for the determination of elastic constants in both the phases. The bulk modulus, shear modulus, Young's modulus, along with the important elastic anisotropy factors and Poisson's ratio are studied in detail. Graphical abstract Image 1 Highlights • Electronic, and optical properties of CaTa 2 O 6 in cubic and orthorhombic phases are studied. • Energy band gaps were equl to 3.08 and 4.40 eV, respectively. • Optoelectronic features are due to Ca-s, Ta-p, O-p orbitals in (c.p.), Ta-p and O-(o.p.) • The Zener factor and Poison's ratio confirm elastically anisotropic characteristics. [ABSTRACT FROM AUTHOR]

Abstract Nitrido silicates are emerged as highly efficient luminescent materials (phosphors) that found considerable industrial application as white light emitting diodes (LEDs) have been studied with respect to band structure and related electronic structure parameters. They have tunable optical properties, as the band gap is of indispensable because it determines both the electrical and optical features of the material, which can be varied by the material composition (by doping technique). It is found also that the nitride (alumo) silicates "Sr 2 Si 5 N 8 : Eu2+" have wide industrial application as highly efficient red-emitting phosphor materials in pc-LEDs. In this report we apply density functional theory (DFT) within the GGA+U approach to study the structural, electronic and optical properties of Eu2+ and Ce3+ doped Sr 2 Si 5 N 8. The total energy has been optimized as a function of the unit cell volume. Electronic structure including, the electronic density of state (DOS), the band structure and the linear optical susceptibility are calculated for the relaxed structure applying the optimized lattice constant. The calculated optical dispersion of dielectric susceptibility are closely related to the corresponding electronic structure and our results are in very good agreement with experimental data. Graphical abstract Image 1 Highlights • Complex studies of band structure for Sr 2 Si 5 N 8 and doped compound with Eu2+and Ce+3 have been done. • Static value of real part for pure Sr 2 Si 5 N 8 is 2.1 while for Eu2+ doped Ce+3 2.6–2.9 • Plasmonic resonances appear at 12.5 eV and for doped – at 10.5 eV. • Main perspectives of eh further improvements of the optical constants are given. [ABSTRACT FROM AUTHOR]

Abstract Optical and magnetic features of the A 2 V 2 O 2 (A = F e and C o) compounds are explored. Density functional theory (DFT) within a framework of FPLAPW (full-potential linearized augmented plane wave) method, as well as generalized gradient approximation plus the Hubbard parameter (GGA+U) and Hubbard on-site Coulomb interaction corrections are applied. U is evaluated assuming constraint generalized gradient approximation for transition metals Fe/Co and V. The calculated band structures for the Fe doped compounds demonstrate the metallic nature while for the Co doped we observe half metallicity possessing 100% spin polarization in the vicinity of the Fermi level. The influence of Fe/Co and V magnetic moment (μ B) on the electronic, magnetic and optical features is explored in details additionally. The optical constants reveal the strong response for A 2 V 2 O 2 (A = F e and C o) in the IR (infra-red region) and UV (Ultra Violet) regions. Graphical abstract Image 1 Highlights • A 2 V 2 O 7 (A = Fe and Co) band structure was studied by functional theory based on FP-LAPW. • The spin polarized structure is more stable as that of without spin structure. • From the Fermi surface Co 2 V 2 O 7 has higher electrical conductivity as compared to Fe 2 V 2 O 7. • Spin polarized magnetic moments is 19.356 μ B (Fe 2 V 2 O 7), 14.002 μ B (Co 2 V 2 O 7). [ABSTRACT FROM AUTHOR]

A photodiode was fabricated as a Schottky contact using Cu-Al-Mn shape memory alloy and p-Si substrate. The alloy was characterized by some characterization techniques such as (SEM), XRD and DSC. The electrical and photovoltaic properties of the prepared Schottky diode were investigated under various illumination intensities and frequencies. The illumination dependent I-V measurements showed that the diode exhibited a photovoltaic behavior. The electronic parameters of the diode were obtained using various theoretical models. The photo transient behavior of the diode was analyzed under solar light. The admittance measurements indicate that the diode exhibits a dispersive capacitance behavior. The results indicate that the Schottky diode could be used in optic device applications. [ABSTRACT FROM AUTHOR]

Nowadays, hydrogen evolution reaction (HER) has gained more attention than the oxygen evolution reaction (OER) in water-splitting. The OER, which involves a four-electron process, is more complex whereas the HER, which involves a two-electron process, is more easy. Hydrogen is one of the promising and efficient energy carriers for renewable and sustainable energy yield. In this work, we have successfully prepared a low-cost electrocatalyst of strontium copper oxide (SCO) through a simple co-precipitation method, followed by an annealing process. The X-ray diffraction is consistent with an orthorhombic structure of SCO. The different modes of vibrations containing Cu, Sr, and O bonds were identified by using the Raman and Fourier transform infrared spectra. The scanning electron microscopy images confirmed that the introduction of sodium dodecyl sulfate (SDS) surfactant allowed to control the size and morphology of the prepared material. Electrochemical measurements indicated that 2 wt% SDS-assisted SCO material exhibited excellent HER performance and high stability. It achieved 166 mV to deliver 10 mA/cm2 and attained the low 124 mV/dec Tafel slope value, indicating that hydrogen evolution reaction followed the Volmer–Heyrovsky mechanism. Compared to the pure and 1 wt% SDS-SCO, 2 wt% SDS-SCO material exhibited a high electrochemically active surface area (ECSA) of 19.3 cm2 and showed a low 0.33 Ω charge-transfer resistance, indicating the presence of supplementary active sites and enhanced electrical conductivity than the reference electrocatalysts. Hence, this work could be considered as a successful approach in exploring the performance of alkaline-based metal oxides in electrochemical hydrogen evolution reactions. • 2 wt% SDS assisted SCO exhibited excellent HER activity and stability. • 166 mV to deliver 10 mA/cm2 achieved and attained 124 mV/dec Tafel slope. • The results indicated Volmer-Heyrovsky process. • 2 wt% SDS-SCO exhibited high ECSA of 19.3 cm2 and low 0.33 Ω R ct. [ABSTRACT FROM AUTHOR]

• The Cu 26.08 Al 2.85 Mn 1.86 Mg/ n -Si/Al Schottky diode was fabricated. • The prepared shape memory alloy was characterized by using DSC and X-Ray Diffraction techniques. • The fabricated device is very sensitive to light. • The prepared device is strongly dependent on the voltage and frequency • The fabricated structure can be utilized in optoelectronic applications. [Display omitted] In this study, the copper-aluminum-manganese-magnesium (Cu–Al–Mn–Mg) shape memory alloy was utilized for the fabricated CuAlMnMg/n-Si/Al structure. The electrical characteristics of the diode were examined by using illumination intensity and frequency dependent current and admittance measurements. Basic electrical parameters such as barrier height (ϕ b0), ideality factor (n), and series (R s) and shunt (R sh) resistances of the generated diode were obtained from the measured current-voltage (I–V) data using thermionic emission (TE) theory. Illumination impact on the diode parameters indicate that the device displays photoconducting behavior. Furthermore, the ϕ b0 value was established from Norde method. There is a good agreement between ϕ b0 values acquired from conventional I-V and Norde method. It was observed that the rise in the applied illumination intensity increased the values of R s and R sh. In addition, the admittance (Y=G+iωC) measurements were carried out in a wide frequency range. As a result of the experimental measurements, it has been shown that the produced CuAlMnMg/n-Si Schottky diode can be operated in optoelectronic practices, especially as a photodiode. [ABSTRACT FROM AUTHOR]

We report here the rational development of MnO 2 nanorods coated tea bag filter paper (TBFP) as a self-standing, bendable, and disposable electrochemical probe for the sensitive and selective H 2 O 2 detection and addresses their challenges in H 2 O 2 sensing via the replacement of 'O' with 'S' in the form of MnS microcubes and its core@shell architecture with MoS 2. The as-configured MnS@MoS 2 /TBFP overwhelms the constrains of conventional electrochemical probes including time and cost consumed electrode surface renewability and catalyst loading progression, and the practice of an insulating binder. The hierarchical open porous architectures of MoS 2 -shell favour the diffusion of H 2 O 2 into the core-MnS microcubes, facilitating an analyte utilization efficacy at both the core and shell architectures. The impacts of core@shell morphological features, replacement of 'O' with 'S', surface defects, and lattice distribution of MnS@MoS 2 toward non-enzymatic H 2 O 2 sensing performances are elucidated using variant electrochemical techniques. With the synergism of uniformly implanted and exposed metallic active sites, efficient electron transfer rate, and high analyte utilization efficiency, MnS@MoS 2 /TBFP exposes the low detection limit (120 nM), excellent sensitivity (650 μA mM−1 cm−2), and wide linear range (500 nM-5 mM) on H 2 O 2 detection. Furthermore, the scrutinized non-enzymatic H 2 O 2 detection concerts of MnS/MoS 2 /TBFP are selective, decisive, repeatable, and stable, constructing the excellent recovery rates in human urine sample analyses. Thus, the collective benefits of free-standing, flexible, binder-less, re-functional, and cost-efficient MnS@MoS 2 /TBFP probe actualize the evolution of affordable and high performance H 2 O 2 sensors. Image 1 ∙ MnS@MoS 2 architectures are prepared by using a simple hydrothermal technique ∙MnS@MoS 2 modified TBFP is used as an electrochemical probe for H 2 O 2 sensing ∙Growth and formation mechanisms of MnS@MoS 2 architectures are illustrated ∙Mn(IV)/Mo(IV) centres engaged H 2 O 2 electroreduction mechanism is schematized ∙MnS@MoS 2 /TBFP establishes effectual non-enzymatic H 2 O 2 sensing performances ∙MnS@MoS 2 /TBFP's real sample H 2 O 2 sensing relevancy is actualized in human urine [ABSTRACT FROM AUTHOR]