Band Gap Energy Research Articles

A‐Site Engineering with Thiophene‐Based Ammonium for High‐Efficiency 2D/3D Tin Halide Perovskite Solar Cells

AbstractTin halide perovskites are the most promising candidate materials for lead‐free perovskite solar cells (PSCs) thanks to their low toxicity and ideal band gap energies. The introduction of 2D/3D mixed perovskite phases in tin‐based PSCs (TPSCs) has proven to be the most effective approach to improving device efficiency and stability. However, a 2D perovskite phase normally shows relatively low carrier mobility, which will be unfavorable for carrier transfer in the devices. In this work, we used a thiophene‐based cation 2‐(thiophen‐3‐yl)ethan‐1‐aminium (3‐TEA) as a spacer to form a novel 2D perovskite phase in TPSCs, which shows the most promising effect on the performance enhancement in comparison with other cations like 2‐(thiophen‐2‐yl)ethan‐1‐aminium (2‐TEA) and benzene‐based 2‐phenylethan‐1‐aminium (PEA). Theoretical calculations reveal that 3‐TEA enables the most compact crystal packing of [SnI6]4− octahedral layers, resulting in the lowest hole effective mass and formation energy in the 2D phase. This effect significantly enhances device efficiency and stability by facilitating more efficient carrier transfer within the 2D phase. These findings indicate that thiophene‐based 2D perovskites are well‐suited for high‐performance TPSCs.

Photovoltaic Efficiency Enhancement of Indium-Free Wide-Bandgap Chalcopyrite Solar Cells via an Aluminum-Induced Back-Surface Field Effect.

Wide-bandgap chalcopyrite materials are attractive candidates for a wide variety of energy conversion devices such as the top cell of tandem-type photovoltaic devices and photoelectrochemical water splitting hydrogen evolution devices. Nevertheless, simultaneous realization of high open circuit voltage (VOC) and high fill factor (FF) values has been challenging, and thus, the photovoltaic performance has been limited. In this article, high VOC and high FF values of wide-gap chalcopyrite CuGaSe2 thin-film solar cells are simultaneously demonstrated using an aluminum-induced back-surface field effect. An independently certified photovoltaic efficiency of 12.25% was obtained from an elemental In-free CuGaSe2:Al (bandgap energy ∼1.7 eV) solar cell (VOC: 0.959 V, short circuit current density: 17.64 mA cm-2, FF: 72.5%). In addition, an over 1 V-VOC CuGaSe2 cell (FF: 74.5%) was obtained even with the use of a conventional CdS buffer layer. Although incorporation of aluminum often leads to degradation of the chalcopyrite solar cell performance, the addition of a small amount of aluminum is found to be effective in enhancing wide-gap chalcopyrite photovoltaic performance.

Predictions of new KTaSn half-Heusler compound for spintronic, thermoelectric and optoelectronic applications: A first-principles study

Structural, electronic, magnetic, elastic, optical, thermodynamic, and thermoelectric characteristics of KTaSn half-Heusler compound are investigated using density functional theory (DFT). GGA-mBJ approximation calculations showed a direct minority spin band gap energy of 1.28 eV and a spin polarization of 100 %. The calculated total magnetic moment and Curie temperature are 2 μB and 380 K respectively. Elastic constants study and formation energy calculation revealed that the material is mechanically and thermodynamically stable and has a ductile nature. 0ptical properties of KTaSn half-Heusler alloy were similarly investigated to highlight its potential for optoelectronic applications. Finally, utilizing Boltzmann's quasi-classical theory, transport properties were studied and yielded a high figure of merit ZT value of 0.62 indicating that the material is suitable for applications in thermoelectric devices.

Optimizing thermoelectric properties of CoTiP half-Heusler via doping with Br-, Se- and Ge atoms using first principle study

The optimization of thermoelectric materials is crucial for advancing energy conversion technologies. This study explores the electrical and thermoelectric properties of Br-, Ge-, and Se-doped CoTiP half-Heusler compounds using the plane-augmented-wave (PAW) method based on Density Functional Theory (DFT) alongside the semiclassical Boltzmann transport equation (BTE) and Debye-Callaway approximation. While previous research has focused on various doping strategies to enhance thermoelectric performance, specific impacts of Br, Ge, and Se doping on the electronic structure of CoTiP remain unexplored. Our analysis reveals that Ge-doped CoTiP exhibits the largest band gap energy of 1.2597 eV, followed by Se- and Br-doped structures with band gaps of 0.8064 eV and 0.678 eV, respectively. The Fermi level shifts towards the conduction band for both Br- and Se-doped alloys while shifting towards the valence band for Ge-doped alloys. Upon doping, we observe significant enhancements in the Seebeck coefficient and electrical conductivity. Power factor (S2σ) enhancements range from 0.01611 W/m K2 for CoTiP0.875Br0.125, 0.03445 W/m K2 for CoTiP0.875Se0.125 and finally, 0.04191 W/m K2 for CoTiP0.875Ge0.125, surpassing undoped material values by up to 93 %. Finally, the optimal value of figure of merit (ZT) increases to 0.65, 0.57, and 0.2 at 900 K, achieved by doping Ge, Se and Br, respectively, at the P site, with performance gain about 92 %. Hence, doping has optimized the thermoelectric performance of the CoTiP half-Heusler.

Enhancement of K storage performance in K3V3-xLax(PO4)4/C cathode materials for potassium-ion batteries via La3+ gradient doping

K3V3(PO4)4(KVP) is recognized as a promising cathode material for potassium-ion batteries (PIBs) due to its high capacity and robust cycling performance. However, its practical application is hindered by low electrical conductivity. This study reports on the synthesis of K3V3-xLax(PO4)4/C materials with varying levels of lanthanum doping, using sol-gel method. We conducted a systematic investigation into the effects of La3+ doping on the crystal structure, morphological characteristics, and electrochemical performance through physicochemical characterization, theoretical calculations, and electrochemical testing. Theoretical calculations suggest that La3+ doping reduces the band gap energy. Electrochemical tests demonstrate that appropriate levels of La3+ doping enhance the electrochemical performance of K3V3-xLax(PO4)4/C. Specifically, K3V2.98La0.02(PO4)4/C shows excellent electrochemical performance. After 100 cycles at 200 mA g−1, the discharge specific capacity reaches 59 mAh g−1, and after 300 cycles at 400 mA g−1, the reversible specific capacity maintains at 48 mAh g−1—nearly twice that of the undoped KVP/C. The enhanced electrochemical performance of these materials is attributed to La3+ doping, which appropriately enlarges the unit cell volume while stabilizing the crystal structure, improving K+ diffusion capability, and boosting the intrinsic electronic conductivity of the material. These findings offer new insights for developing cost-effective and high-performance cathode materials for PIBs.

Molecular modeling analyses of functionalized cellulose

Functionalization of cellulose with nanomaterials and functional groups is essential for enhancing its properties for specific applications, such as flexible sensors and printed electronics. This study employs Hartree Fock (HF) and Density Functional Theory (DFT) calculations to investigate the vibrational spectra of cellulose, identifying DFT: B3LYP/3–21 g** as the optimal model aligning with experimental spectra. Using this model, we examined the impact of functionalizing cellulose with various groups (OH, NH2, COOH, CH3, CHO, CN, SH) and graphene oxide (GO) on its electronic properties. The results indicate that cellulose functionalized with GO (Cellulose-GO) has the lowest bandgap energy (0.1687 eV), and improvements in reactivity, stability, and electronic properties were confirmed through Molecular Electrostatic Potential (MESP) and Total Dipole Moment (TDM) analyses. The spectrum of Density of States (DOS) for the cellulose functionalized with different groups shows several peaks, indicating various energy levels where electronic states are concentrated. The Projected Density of States (PDOS) analysis reveals how different functional groups affect the electronic structure of cellulose. Moreover, the (Cellulose-GO) composite was characterized using an Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectrometer, revealing interaction through the OH group of CH2OH, as indicated by a new band at 1710 cm−1, consistent with theoretical predictions. Overall, this study demonstrates that functionalization with GO enhances cellulose’s responsiveness, degradation, and electrical properties, making it suitable for applications in flexible electronic devices and protective barriers against corrosion.

Adjustable emission color by gadolinium tungstate phosphor for multiple applications

Crystalline monoclinic structure Gd2(WO4)3 phosphors were prepared by calcining a co-precipitated precursor at 800°C. The XRD patterns exhibited strong signals at the (-221) and (023) planes. The UV-vis absorption spectrum showed strong absorbance in the UV range, with an estimated bandgap energy of about 4 eV. When excited the synthesized phosphors emitted green (Tb3+), red (Eu3+), yellow (Dy3+), and reddish orange (Sm3+), respectively. Utilizing these luminescent properties, flexible composite sheets were fabricated by mixing the phosphors with PDMS. When applied to UV-LED chips. The composites could be molded into various shapes figures. Under normal light, the composites appeared white, but under UV light, they displayed distinct colors, demonstrating their potential for anti-counterfeiting applications. Additionally, when the synthesized phosphor powder was sprinkled onto a glass substrate with fingerprints and illuminated with a UV lamp, the unique features of the fingerprints were clearly visible, indicating potential use in forensic fingerprint analysis.

Role of SiO2, TiO2, and Fe3O4 adsorbed on glycine for remediation of heavy metals and antibacterial activity in water

Metals have a tendency to accumulate in the environment and can have carcinogenic effects. Accordingly, this study used density functional theory (DFT) calculations to investigate the adsorption of different metal ions on the glycine surface. Glycine has attracted a lot of research interest because of its remarkable metal-binding properties and cost effectiveness. Accordingly, to improve glycine’s adsorption capacity, it has been combined with SiO2, TiO2, and Fe3O4, creating a glycine-metal oxide nanocomposite through hydrogen bonding. After optimizing the structures at their energy minima at the B3LYP/6-31G(d, p) level of theory, the following analyses were carried out: total dipole moment (TDM), frontier molecular orbitals (FMOs), reactivity indexes, and molecular electrostatic potential (MESPs). The study of TDM, FMOs, reactivity indexes, density of states (DOS), and UV-Vis absorption analysis demonstrated the improved reactivity of glycine due to functionalization with SiO2. Additionally, the results showed that, compared to the glycine, the glycine/SiO2 surface experiences a greater degree of charge redistribution as a result of more hydrogen bonds being formed with adsorbate molecules. Thus, the study successfully extracted Cr, Fe, Co, Ni, Cu, As, Cd, and Pb from wastewater by demonstrating their selectivity for the glycine/SiO2 nanocomposite. The findings show that Ni had a stronger adsorption for glycine/SiO2 than the others as TDM increased (34.040 Debye), band gap energy decreased significantly (0.249 eV), and reactivity indices got improved. Additionally, the IR spectra were calculated and compared to the experimental data, which revealed remarkable frequency changes due to intermolecular interactions. HR-TEM scans validated the dispersion of SiO2 NP on the glycine surface with minimal aggregation. Furthermore, the antibacterial activity of glycine-amino acid-based surfactants was assessed, and the results show that glycine/SiO2 nanocomposites exhibited antibacterial efficacy against Gram-positive and Gram-negative microorganisms. These findings highlight the glycine/SiO2 nanocomposites for remediation of heavy metals and have antibacterial activity for treating pathogenic bacteria.

Electrochemical studies of ytterbium doped Cu/Co nanoparticles synthesized by green fabrication using Callistemon viminalis leaves extract

AbstractBACKGROUNDUtilization of phytochemicals for the preparation of metal oxides nanocomposites has been proven to be a best alternate of chemical synthesis methods. Here, we have extracted, isolated and characterized the phytochemicals of Callistemon viminalis plant extract and utilized them as biofuel in the synthesis of Cu/Co and doped Cu/Co nanoparticles. Callistemon viminalis has been shown to have reducing and stabilizing properties. The plant extracts contain a variety of bioactive substances, including tannins, vitamins, amino acids, saponins, inositol, alkaloids, flavonoids, and terpenes. The use of plant extracts in the synthesis of NPs is a quick, dependable, nontoxic, benign, environmentally friendly, and cost‐effective method. Thus, in the present work, the Callistemon viminalis leaves extract a synthesis of Cu/Co nanoparticles and ytterbium doped Cu/Co nanoparticles, and these nanoparticles were characterized by optical properties (UV), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), X‐rays diffraction (XRD), and electrochemical application.RESULTSSynthesis of Cu/Co nanoparticles and ytterbium doped Cu/Co nanoparticles at room temperature have been successfully done using Callistemon viminalis aqueous leaf extract. Products were confirmed by conducting UV‐ visible spectrophotometry, FTIR, SEM, and XRD confirming the formation of cubic shaped Cu/Co nanoparticles of average diameter of 14 nm. The aqueous leaf extract acted as a capping agent and the existence of organic functional groups were confirmed by FTIR. Upon varying the Yb content in Cu/Co, the particle's size obtained from SEM showed a decrease in size. The band gap energies were also reduced with Yb doping. The stability of the produced NPs was investigated using linear sweep voltammetry LSV on this special and innovative metal oxide electrode. The LSV analysis has shown an elevation in the scan rate detection with an increase in voltage. 55.6 μA current was detected at 10 V for Cu/Co NPs. Ytterbium doped nanoparticles have shown 471.3 μ current voltage value at scan rate of 10 V. Observed value of current of synthesized Cu/Co NPs was 5.7 μA and the observed current of doped Yb(Cu/Co) was 12.5 μA. The increase in current values of dopant Cu/Co nanoparticles is due to the higher pore volume and surface area of copper, which promotes the transfer of electrons, so the current density is greater of the doped material than the composite NPs. The electrical resistivity of Cu/Co nanoparticles has shown a decline with elevation in current indicating its semiconducting nature.CONCLUSIONIn summary, biologically synthesized Cu/Co and ytterbium doped Cu/Co nanoparticles at room temperature have been successfully synthesized based on the greener approach using Callistemon viminalis aqueous leaf extract. The utilization of the Callistemon viminalis plant‐mediated approach, which makes the procedure more affordable and environmentally benign than chemical synthesis, is one of the study's major contributions. © 2024 Society of Chemical Industry (SCI).

Origin and Potentialities of the Selective Host‐Matrix Effect in Hydrogenated III‐V‐N Alloys.

AbstractIn a previous study, puzzling experimental results regarding the neutralization of N effects on the bandgap energy in the hydrogenated In0.21Ga0.79As0.975N0.025 alloy were explained by theoretical investigations revealing the occurrence of a novel phenomenon: thermal annealing changes the InGaAs host‐matrix by making it able to exert a selection of the N–H complexes responsible of the N neutralization. In view of technological applications of this effect, the underlying selective host‐matrix model was carefully checked here by theoretically investigating InGaAsN alloys of different compositions ranging from Ga‐rich to In‐rich. As a most important result, such an extensive investigation inspired a comprehensive explanation of the origin of the host‐matrix effect which clarifies how the effect works, firmly establishes its occurrence, gives indications for a bandgap tuning based on a matrix design, sets conditions for its extension to other III‐V‐N alloys and suggests ways to induce fine changes of the alloy mechanical behavior.

Characterization of PbMo0.3W0.7O4 Crystal: A Potential Material for Photocatalysis and Optoelectronic Applications

AbstractPbMo0.3W0.7O4 semiconductor crystal, which contains the balanced ratios of Mo and W, is grown for the first time by Czochralski method. The structural and optical properties of the crystal are investigated in detail in the present study. Structural analysis shows that crystal has tetragonal structure like PbMoO4 and PbWO4 compounds. The optical characteristics are studied by transmission, Raman, FTIR and photoluminescence methods. The bandgap energy is found to be 3.18 eV, and the positions of the conduction and valence bands are determined. The vibrational characteristics are studied by means of Raman and FTIR spectroscopy techniques. Photoluminescence spectrum presents three peaks around 486, 529, and 544 nm which fall into the green emission spectral range. Taking into account the properties of the compound, it is stated that PbMo0.3W0.7O4 (or Pb(MoO4)0.3(WO4)0.7) has the potential to be used in water splitting applications and optoelectronic devices that emit green light.

Tunable Optical Properties and Relaxor Behavior in Ni/Ba Co-Doped NaNbO3 Ceramics: Pathways Toward Multifunctional Applications

In this study, Ni/Ba co-doped NaNbO3 ceramics (NBNNOx) were synthesized using a solid-state method to explore the effects of Ni2+ and Ba2+ ion substitution on the structural, optical, and dielectric properties of NaNbO3. X-ray diffraction (XRD) confirmed that the ceramics retained an orthorhombic structure, with crystallinity improving as the doping content (x) increased. Significant lattice distortions induced by the Ni/Ba co-doping were observed, which were essential for preserving the perovskite structure. Raman spectroscopy revealed local structural distortions, influencing optical properties and promoting relaxor behavior. Diffuse reflectance measurements revealed a significant decrease in band gap energy from 3.34 eV for undoped NaNbO3 to 1.08 eV at x = 0.15, highlighting the impact of co-doping on band gap tunability. Dielectric measurements indicated relaxor-like behavior at room temperature for x = 0.15, characterized by frequency-dependent anomalies in permittivity and dielectric loss, likely due to ionic disorder and structural distortions. These findings demonstrate the potential of Ni/Ba co-doped NaNbO3 ceramics for lead-free perovskite solar cells and other functional devices, where tunable optical and dielectric properties are highly desirable.

Effect of Al-, In-, and Mg-doping in the ZnO on the structural, electrical, and optical properties of ZnO/CH3NH3PbI3 heterostructure

The creation of ZnO/CH3NH3PbI3 heterostructures with Aluminum (Al), Magnesium (Mg), and Indium (In) doped ZnO serving as an electron transport layer is the aim of this work. A favorable orientation for the CH3NH3PbI3 absorber layer crystallizes in the tetragonal phase [220], while ZnO crystallizes in the hexagonal phase [100]. This information is yielded by x-ray diffraction analysis. Al, In, and Mg doping of the transport layer has a significant effect on the optical characteristics like absorption and extinction coefficients, optical gaps, and optical and electrical conductivity. The UV–visible characterization of the heterostructures reveals that n-type doping can raise ZnO gap energy from 3.15 to 3.42 eV. The band gap energy of CH3NH3PbI3 is around 1.53–1.55 eV. Additionally, the absorption coefficient of each sample is high, it exceeds 105 cm−1. The ZnO thin films, both undoped and doped (with Al, In and Mg) exhibit an increase in refractive index from 1.97 to 2.13. The best dopant is found to be In. The refractive index of films composed of CH3NH3PbI3 is 3.13.

Impact of hydrochloric acid doping on polyaniline conductivity and piezoelectric performance in polyaniline/bismuth oxyiodide nanocomposites

This study investigates the impact of hydrochloric acid (HCl) doping, ranging from 0.2 M to 1.25 M, on the conductivity of polyaniline (PANI) and the piezoelectric performance of polyaniline/bismuth oxyiodide (PANI/BiOI) nanocomposites (NCs). Two distinct methods for fabricating NCs based on PANI and bismuth oxyiodide (BiOI) are proposed. Two distinct methods for fabricating PANI/BiOI NCs are proposed, and their optical and electrical properties are systematically examined. The direct allowed energy bandgap of the NCs is found to be approximately 1.9 eV. The piezoelectric performance, attributed to the 2D Janus structure of BiOI, is explored in detail, with the bulk piezoelectric coefficient measured at 1.43 (65) pm/V. Sensitivity to pressure interaction reached 21.1 (92) mV/bar, and the generated power was 5.09 nW for air pressure excitation in a composite consisting of 37.5 wt% BiOI and 62.5 wt% PANI doped with 0.2 M HCl, fabricated in-situ. The results demonstrate precise control over key parameters, including the fabrication method, sample thickness, HCl doping concentration, and BiOI content, highlighting the significant potential for enhancing nanogenerator functionality. These findings provide valuable insights into improving the performance of piezoelectric materials for energy harvesting technologies.

Tunable photo-response in the visible to NIR spectrum range of Germanium-based junctionless nanowire transistor

In this paper, the phototransistor behavior is investigated in the germanium-on-insulator (GeOI)-based junctionless nanowire (JL-NW) transistor under various light conditions. High responsivity and photosensitivity are attributed in the fully depleted regime within the visible and near-infrared bands. The impact of light is also investigated in detail on the electronic and transfer characteristics such as energy bandgap, carrier distribution, electrostatic potential, electric field, generation and recombination rates. Further, the channel doping and thickness are tuned to optimize the optical responsivity. The significant tunability of responsivity is observed with increasing channel thickness. The device exhibits fast optical switching performance, which is further enhanced at higher input light power. Overall, at the nanoscale dimension, our proposed phototransistor demonstrates better detectivity with a significantly smaller illumination area. Thus, the GeOI-based JL-NW phototransistors can be used for imaging (visible wavelength range) and bioimaging (near-infrared wavelength range) applications in advanced technology nodes.

Investigating the impact of ITO substrates on the optical and electronic properties ofWSe2monolayers.

Two-dimensional (2D) materials, particularly transition metal dichalcogenides (TMDCs), have gathered significant attention due to their interesting electrical and optical properties. Among TMDCs, monolayers of WSe2exhibit a direct band gap and high exciton binding energy, which enhances photon emission and absorption even at room temperature. This study investigates the electronic and optical properties of WSe2monolayers when they are mechanically transferred to indium tin oxide (ITO) substrates. ITO is a transparent conducting electrode (TCE) used in many industrial opto-electronic applications. Samples were mechanically transferred under ambient conditions, consequently trapping an adsorbate layer of atmospheric molecules unintentionally between the monolayer and the substrate. To reduce the amount of adsorbates, some samples were thermally annealed. Atomic force microscopy (AFM) confirmed the presence of the adsorbate layer under the TMD and its partial removal after annealing. X-ray photoelectron spectroscopy (XPS) confirmed the presence of carbon species among the adsorbates even after annealing. Photoluminescence (PL) measurements show that WSe2remains optically active on ITO even after annealing. Moreover, the luminescence intensity and energy are affected by the amount of adsorbates under the WSe2monolayer. Scanning Tunnelling Spectroscopy reveals that the TMD monolayer is n-doped, and that its band edges form a type I band alignment with ITO.. Surface potential measurements show a polarity change after annealing, indicating that polar molecules, most likely water, are being removed. This comprehensive study shows that a TCE does not quench WSe2luminescence even after a prolonged thermal annealing, although its optical and electronic properties are affected by unintentional adsorbates. These findings provide insights for better understanding, controlling, and design of 2D material heterostructures on TCEs.

Evaluating the antidiabetes and antioxidant activities of halogenated Schiff bases derived from 4-(diethylamino)salicylaldehyde: in vitro antidiabetes, antioxidant and computational investigation

Six Schiff bases with general name 5-(diethylamino)-2-(((halophenyl)imino)methyl)phenol (where halo = 4-fluoro (H1), 2-fluoro (H2), 2-bromo (H3), 4-bromo (H4), 4-chloro (H5) and 3-chloro-4-fluoro (H6)) were prepared by the condensation reaction between 4-(diethylamino)salicylaldehyde and suitable halogenated aromatic amines. The six halogenated Schiff bases were elucidated using different spectroscopic techniques and the structure of H3 and H6 were confirmed using single-crystal X-ray crystallography. The bond lengths of C7–N1, C7–C8 and C8–C9 obtained from structural analysis for both compounds depicted their enol-tautomeric characteristic form. The Hirshfeld analysis revealed that H‧‧‧H intermolecular contacts contributed most towards the Hirshfeld surfaces of both H3 (47.6%) and H6 (39.9%). Quantum chemical calculation studies showed that H1 and H2 have the highest and lowest energy band gap (∆E = 3.80 eV for H1 and ∆E = 3.73 eV for H2), depicting H2 and H1 as the most and least chemically reactive respectively among all the compounds. α-Amylase and α-glucosidase assay were used to evaluate the antidiabetes prowess of the synthesized compounds. All the compounds exhibited lower IC50 values than acarbose (reference drug) in α-amylase assay experiments and H5 with lowest IC50 value of 63.54 μM could be suggested to have the highest α-amylase inhibitory potential among the test samples. For α-glucosidase assay, H1–H6 displayed good antidiabetic potential. However, none of the compounds outshined acarbose with H6 having highest α-glucosidase inhibitory potential when compared to others i.e., IC50 of H6 = 60.89 μM and IC50 of acarbose = 51.42 μM. We measured the antioxidant potential of H1–H6 exploring 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and ferric reducing ability power (FRAP) assays. The DPPH as well as NO radical scavenging assay showed that all the compounds exhibited excellent antioxidant results with some of the compounds surpassing catechin (reference drug). Compound H5 with IC50 values of 30.32 mM and 31.73 mM outshined catechin with IC50 values of 31.17 mM and 140.62 mM for DPPH and NO assays respectively. All the compounds fell within the threshold of Lipinski’s Ro5 projecting them as orally bioavailable and less toxic future therapeutics.

Fe-doped SrZrO3 nanostructures as photocatalyst: Solid-state synthesis and UV-light driven eradication of thymol blue dye

In this study, pristine and Fe-doped Strontium Zirconate (SZF0 and SZF10) nanophosphors were synthesized using a simple solid-state method. The structural and optical properties of the synthesized materials were extensively characterized using Powder X-ray Diffraction (PXRD), UV–visible spectroscopy, Raman spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), and Transmission Electron Microscopy (TEM). The PXRD analysis confirmed the multiple phase purity and crystallinity with #96–900–0228 (orthorhombic) and #96–153–8368 (cubic) of the samples, having calculated crystallite size of 22.2 nm for SZF0 and 21.4 nm for SZF10. UV-visible spectroscopy revealed the quenching of bandgap energies from 3.24 eV to 1.65 eV for effective UV-light absorption. Raman spectroscopy provided insights into the prominent vibrational modes (Ag, B2g, and B3g) and structural integrity of the doped and undoped samples. Morphological analysis through FESEM and EDAX affirmed the agglomerated cluster clubbed morphology and stated elements of the SZF10 sample with particle size distribution averaging at 22.11 nm which was well aligned with PXRD results. Meanwhile, the TEM analysis confirms the same with high crystallinity. The photocatalytic activity of the synthesized SZF10 sample was evaluated by degrading TB dye under various experimental conditions. The results show a prominent degradation rate of 81.04 % at the 90th minute. The same results were utilized in studying the kinetics of the degradation process which align with the 1st-order kinetics with k and R2 values of 0.00737 and 0.98034, respectively. The influence of different parameters such as pH, catalyst dosage, and dye concentration on the degradation efficiency was systematically studied to obtain the optimum values.

Impact of the host lattice on crystallographic, Raman, optical, and luminescent properties on the terbium ion

AbstractA comparative study of the Gd2O3:Tb and Y2O3:Tb nanoparticles (NPs) was presented to examine the influence of the host lattices on the crystallographic phase, surface characteristics, optical properties, Raman effect, and photoluminescence properties. Cubic shapes Gd2O3:Tb and Y2O3:Tb NPs with an estimated crystalline size of 17 and 11 nm were recorded from the X‐ray diffraction pattern, respectively. Comparative absorption spectra of both oxides NPs were presented to examine the dispersibility, colloidal stability, and optical behavior of the NPs. Energy bandgap values were estimated to monitor the optical characteristics of the metal oxides in the UV/Vis region. Fourier transform infrared was recorded to confirm the surface‐attached water and organic moieties. The Raman spectra of metal oxides were recorded to examine the symmetrical dis‐order and polarizability of the vibrational bands. The ionic radius of the atoms distorts the bond structure resulting in it greatly influenced the vibrational bands of the materials. The emission spectra certified the effective doping of the luminescent Tb3+‐ion in the metal oxide host lattices. Raman spectra and emission spectra validated the crystal symmetry imperfections; subsequently, the efficiency of the Raman active modes and emission transitions was greatly influenced. In a comparative analysis, Y2O3:Tb NPs exhibited higher luminescence intensity in comparison with the Gd2O3:Tb NPs.

A DFT study on the role of excitons and electric field-induced symmetry breaking and topological properties of ZrBr

The control of band gap and topological properties is a crucial objective in the field of materials science, particularly for the application of 2D materials such as topological insulators. Zirconium monobromide (ZrBr), a topological insulator with band inversion, holds significant potential for various applications. In this study, we used Density Functional Theory (DFT) with different approximations namely, Generalized Gradient Approximation (GGA) with and without spin orbit coupling (SOC) as well as hybrid functional to investigate the electronic structure and the band gap of this compound. In addition, we introduced the excitonic effect by considering GW plus Bethe–Salpeter equation (GW-BSE) to compute the optical band gap and quasi-particle energy. We found that ZrBr present a low static dielectric function and weak exciton binding energy, generally lower than those of conventional semiconductors. This behavior is due to the reduced Coulomb interaction in the material. To further explore the material’s behavior, we apply an electric field in three directions to observe symmetry breaking and its impact on band gap tuning. This comprehensive analysis aims to explore the understanding and the potential applications of ZrBr as a topological insulator.