Wavelength Gap Research Articles

Improving Structural, Optical, and Ionizing Absorption Features of G-T-B Glass System by Doping Different Concentration of Sm2O3

The current work aims to prepare a glass series described by the chemical formula of 20TeO2-35MgO-10GeO2-(35-x) B2O3-xSm2O3, where x = 2.5, 5, and 7.5 mol% for radiation shielding applications. The glass preparation was performed under a melting temperature of 1100 °C, followed by annealing at 350 °C. The X-ray diffraction was used to show the crystalline phase of prepared glasses, which confirms that all prepared samples are amorphous. The ultraviolet-visible absorption spectra for the prepared glass samples were detected using the Shimadzu 3101 spectrophotometer over the wavelength range of 300–1100 nm. Based on the UV/Vis absorption spectrum, several optical properties were determined for the prepared glass samples, including band gap (eV), Urbach energy (eV), refractive index, transmission (%), reflection loss, metallization, optical electronegativity, optical basicity, electron polarizability, and cutoff wavelength (nm). Additionally, the Makishima-Makinze model theory was applied to investigate the mechanical properties of the prepared samples, where the increase of Sm2O3 concentrations within the prepared samples decreases the mechanical moduli while increasing the microhardness of the prepared glass samples. Furthermore, the effect of Sm2O3 addition on the radiation shielding properties of germanium boro-tellurite glasses was examined over the gamma-ray energy range of 0.0332–2.506 MeV using the Monte Carlo simulation technique. The increase in Sm2O3 content enhanced the radiation shielding parameters of prepared glass samples, making these glasses suitable for shielding applications.

Design of an all-optical tunable 2D photonic crystal in As2S3 film

Amorphous arsenic trisulphide (As2S3) chalcogenide glass is widely used in photonics and optoelectronics due to its wide transparency in the infrared spectral range, its high linear refractive index (nAs2S3 = 2.42), which can be significantly modified by light with a suitable wavelength, and its important optical nonlinearity. In this work, we report the design of an all-optical tunable two-dimensional photonic crystal in a geometry which consists in a hexagonal lattice of holes patterned in As2S3 film with the aim to exhibit photonic band gap in the near infrared domain. We numerically investigated the possibility to all-optically tune the photonic band gap of an already patterned photonic crystal in As2S3 modifying only its refractive index by illumination with light of wavelength λ at the band gap energy (λ = 514.5 nm) or shorter, without affecting the lattice geometry. The influence of the variation of As2S3 refractive index (Δn) on the spectral position of the band gap and on its width has been determined for the light-induced modification of Δn up to the value of 0.09. For this value of Δn, a shift of almost 50 nm of the central wavelength of the photonic band gap has been obtained. These results are of great interest in the field of photonics offering a versatile solution to fabricate all-optical tunable photonic crystals in any optical material whose refractive index can be modified by light.

The Ice Cloud Imager: retrieval of frozen water column properties

Abstract. The Ice Cloud Imager (ICI) aboard the second generation of the EUMETSAT Polar System (EPS-SG) will provide novel measurements of ice hydrometeors. ICI is a passive conically scanning radiometer that will operate within a frequency range of 183 to 664 GHz, helping to cover the present wavelength gap between microwave and infrared observations. Reliable global data will be produced on a daily basis. This paper presents the retrieval database to be used operationally and performs a final pre-launch assessment of ICI retrievals. Simulations are performed within atmospheric states that are consistent with radar reflectivities and represent the three-dimensional (3D) variability of clouds. The radiative transfer calculations use empirically based hydrometeor models. Azimuthal orientation of particles is mimicked, allowing for the consideration of polarisation. The degrees of freedom (DoFs) of the ICI retrieval database are shown to vary according to cloud type. The simulations are considered to be the most detailed performed to this date. Simulated radiances are shown to be statistically consistent with real observations. Machine learning is applied to perform inversions of the simulated ICI observations. The method used allows for the estimation of non-Gaussian uncertainties for each retrieved case. Retrievals of ice water path (IWP), mean mass height (Zm), and mean mass diameter (Dm) are presented. Distributions and zonal means of both database and retrieved IWP show agreement with DARDAR. Retrieval tests indicate that ICI will be sensitive to IWP between 10−2 and 101 kg m−2. Retrieval performance is shown to vary with climatic region and surface type, with the best performance achieved over tropical regions and over ocean. As a consequence of this study, retrievals from real observations will be possible from day one of the ICI operational phase.

Effect Of Annealing Temperature On The Optical And Structural Properties Of Zinc-Doped Cd2SnO4 Thin Films Prepared By Dip-Coating Method

As demand for solar PV modules steadily increases studies on cheaper alternative TCO materials, with low resistivity and high transmittances in the visible spectrum to replace ITO are been undertaken. Among TCO materials considered as alternative to Indium Tin Oxide (ITO) is Cd2SnO4, owing to its availability in large quantities at relatively lower costs. Studies on optical properties of N2 and F2 doped Cd2SnO4 films have revealed increased transmittance 99%, and reduced band gap 3.3 eV. On the other hand Fe doped films have been observed to exhibit higher refractive indices, extinction and absorption coefficients with lower transmittance and optical band gap. Although studies have been carried out on Zinc doped Cd2SnO4 films, the effect of annealing temperature on the properties of the films have not been reported. This study investigated the effect of annealing temperature on the optical and structural properties of Zinc-doped Cd2SnO4 films. Thin films of Zincdoped Cd2SnO4 were prepared by mixing 0.1 M Cadmium Acetate with 0.1 M Tin II Chloride in ratio 1:1 to prepare Cd2SnO4 which was doped with 0.1 M Zinc Nitrate then dip-coated on clean glass substrates. The coated substrates were dried at room temperature and annealed in air the films annealed at 350 o C, 400 o C and 450 o C for 90 minutes Optical transmittance and reflectance were measured in wavelength range 200-1200 nm and with the results: prominent XRD peak oriented in the (2 0 0) direction, transmittance of 78.7% at 700 nm wavelength, absorption coefficient of 3.891 - 5.591 x 104 cm-1 , extinction coefficient of 0.1852 - 0.2126, refractive indices of 1.983-2.121 at 588 nm wavelength and band gap values range 3.45-3.65 eV. Annealing was observed to reduce refractive index and does not affect transmittance therefore doesn’t enhance suitability of films as TCO materials for Photovoltaic applications.

Investigation on growth, structural, mechanical, linear and nonlinear optical properties of DiLithium Fumarate TetraHydrate single crystal

In this work reports on the growth and characterization of semiorganic NLO single crystal of DiLithium Fumarate TetraHydrate (DLFTH) using a slow evaporation technique. The crystal structure was an orthorhombic crystal system with the centrosymmetric space group Pbcn, as demonstrated by single crystal X-ray diffraction (SCXRD) investigations. The UV–Vis-NIR spectrum is used to derive optical parameters, such as the lower cut off wavelength (277 nm) and optical energy band gap Eg = 4.98 eV. DLFTH crystals belongs to hard material category using Vickers microhardness test. From NLO studies, the nonlinear optical parameters were studied, such as the nonlinear refractive index (n2), absorption coefficient (β) and third order NLO susceptibility (χ3). The crystal has the properties of saturable absorption and self-defocusing nature. Third order NLO susceptibility (χ3) were found to be 4.14384 × 10-10esu. The higher χ3 number is due to the presence of hydrogen bonds between C-H-O and O-H-O atoms. Therefore, we confirm that it’s applicability for optical device applications.

(Ce, Nd) co-doped TiO2 NPs via hydrothermal route:Structural, optical, photocatalytic and thermal behavior

Rare earth (Ce, Nd) doped/co-doped titania (TiO2) nanoparticles were successfully produced by hydrothermal route. Titanium isopropoxide (IV), cerium nitrate hexahydrate and neodymium nitrate hexahydrate were utilized as raw/starting materials. The effect of Ce and Nd doping/co-doping in TiO2 were studied through different complementary tools such as XRD, FTIR, FE-SEM, EDX, XPS, UV–Visible, PL, photocatalytic and thermal analysis. XRD spectra revealed anatase tetragonal phase and cubic phase due to titania and ceria nanoparticles respectively. The crystallite size, lattice constants, volume and no. of unit cell were determined through XRD data. Optical studies revealed the band gap, urbach energy, extinction coefficient, refractive index, optical conductivity and photoluminescence emission wavelength. FTIR spectra investigated the chemical bondings and functional groups present in prepared samples. Optical absorption spectra confirmed that absorption edge is red shifted, indicating a decrease in band gap from 3.5 to 3.0 eV with the incorporation of rare earth ions (Ce, Nd) in TiO2 matrix. The rate of electron-hole pair recombination was reduced through co-doping of (Ce, Nd) in TiO2 lattice as exhibited by reduction in intensity of photo luminescence spectra. The photocatalytic efficiency was enhanced with the integration of rare earth metal ions in TiO2 matrix for different dyes such as rhodamine B (RhB) and malachite green (MG) with visible light irradiation. The degradation efficiency of (Ce, Nd) co-doped TiO2 NPs against RhB and MG dyes was found to be 89 and 95 % respectively. TGA analysis was carried out to find weight loss during different thermodynamic phases such as dehydration, decomposition and combustion, and crystallization. Various thermodynamic parameters such as activation energy, entropy and enthalpy were estimated by thermal analysis.

A Mitochondria-Targeting Fluorescent Probe for the Dual Sensing of Hypochlorite and Viscosity without Signal Crosstalk in Living Cells and Zebrafish.

Hypochlorite (ClO-) and viscosity both affect the physiological state of mitochondria, and their abnormal levels are closely related to many common diseases. Therefore, it is vitally important to develop mitochondria-targeting fluorescent probes for the dual sensing of ClO- and viscosity. Herein, we have explored a new fluorescent probe, XTAP-Bn, which responds sensitively to ClO- and viscosity with off-on fluorescence changes at 558 and 765 nm, respectively. Because the emission wavelength gap is more than 200 nm, XTAP-Bn can effectively eliminate the signal crosstalk during the simultaneous detection of ClO- and viscosity. In addition, XTAP-Bn has several advantages, including high selectivity, rapid response, good water solubility, low cytotoxicity, and excellent mitochondrial-targeting ability. More importantly, probe XTAP-Bn is successfully employed to monitor the dynamic change in ClO- and viscosity levels in the mitochondria of living cells and zebrafish. This study not only provides a reliable tool for identifying mitochondrial dysfunction but also offers a potential approach for the early diagnosis of mitochondrial-related diseases.

Coastal aquatic pollutants degradation using ZnCo2O4 nanorods

Water pollution has caused problems in coastal areas, rivers, lakes, and other important water sources around the world as a result of inappropriate waste management. Meanwhile, these pollutants are harmful to humans and aquatic life. Textile dye effluent methyl orange (MO) was used in this work for dye degradation studies employing nanocomposites. As a result, the importance of synthesizing pure ZnO and Co3O4 nanoparticles with composites of ZnCo2O4 (zinc cobaltite) nanorods in three various proportions (90:10, 75:25, and 50:50) is emphasized in this study. Many advanced approaches were used to assess the various features of these materials, including size and shape. Fourier transform infrared (FT-IR) spectroscopy was used to determine the vibrational modes of the materials. The absorption measurements were then carried out using UV–vis spectroscopic techniques, and the photocatalytic breakdown of MO was done under visible light irradiation. The findings revealed that pure materials were inadequate for visible light activity, resulting in decreased degradation efficiencies. Spinel cobaltite structures have potential degradation efficiency under visible light, while ZnCo2O4 (50:50) catalyst has superior degradation efficiency of 59.8% over MO. The crystallite size, morphology, functional group, absorption wavelength, and band gap all play important roles in enhancing the material's photocatalytic activity under visible light. Meanwhile, ZnCo2O4 spinel structures are crucial for increasing charge carriers and reducing electron-hole recombination. As a result, zinc cobaltite minerals are widely used in industrial dye degradation applications.

One-dimensional photonic crystals based on porous anodic alumina: Optical and morphology changes under thermal and chemical treatments

One-dimensional photonic crystals (1D PCs) based on porous anodic aluminium oxide (AAO) are promising for light manipulation and sensing. As-prepared AAO, being amorphous material, suffers degradation in acidic and alkaline media. It is commonly known that the chemical stability of AAO increases drastically after thermal treatment. Here, the effect of annealing up to 1200 °C on the morphology and the optical properties of AAO PCs is studied. The two-step crystallization of as-prepared AAO at 860 and 1190 °C leads to a two-step blue shift of the central wavelength of photonic band gap (PBG) and the decrease in PBG depth, whereas the Q-factor of the PBG enhances. The observed changes in optical transmittance spectra of PCs are mainly attributed to the increase in pore diameter, the formation of crystalline particles of alumina polymorphs, and the removal of impurities. Annealed AAO PCs demonstrate much higher stability of optical parameters during exposure in acidic media compared to the as-prepared ones. Thermal treatment at 600 °C results in 30% decrease in the rate of the PBG shift during chemical etching. Furthermore, AAO crystallization into a mixture of low-temperature alumina polymorphs at 860 °C leads in a negligible change in transmittance spectra even after chemical etching in 1 M HCl for 75 h. The excellent stability achieved for the annealed AAO PCs in aggressive media proves the perspectives of their application as the optical sensors with long-term stability.

Effect of zirconium oxide nanoparticles on thermal, optical, and radiation shielding properties of Bi2O3-B2O3-MnO2 glasses

This study has explored the DSC, UV–Vis absorption spectroscopy, gamma ray and neutron shielding properties of Bi2O3-B2O3-MnO2: ZrO2 glasses. It demonstrates a unique approach to photon shielding analysis using JENDL/PD-2016 photonuclear data and employs a validated spherical neutron model for neutron shielding. Five transparent glasses were prepared with the chemical composition (in mol%) of 29Bi2O3-70B2O3-(1-x)MnO2: xZrO2, and labeled as MZ0.00 (for x = 0), MZ0.25 (for x = 0.25), MZ0.50 (for x = 0.5), MZ0.75 (for x = 0.75) and MZ1.00 (for x = 1). The glass ceramic nature of the samples has been characterized by DTA thermograms. The glass forming ability parameters (Kgl, S & H) were found to be highest for the sample MZ1.00. The UV–Visible optical absorption spectra have been interpreted, and hence the cut-off wavelength (λcut-off) and optical band gap (Eo) were evaluated. The absorption spectra have revealed the co-existence of manganese ions in three stable valence states Mn4+, Mn3+ and Mn2+ in the samples. When ZrO2 nanoparticles were added in the composition up to x = 0.50 mol%, the red shift in the cut-off wavelength (λcut-off) with gradual shrinkage in optical band gap (Eo) has been observed. Also, the linear and non-linear optical parameters viz., refractive index (no), non-linear refractive index (n2), linear optical susceptibility (χ(1)) and non-linear optical susceptibility (χ(3)) have been evaluated. These parameters showcased that B-O, Bi-O, Mn-O, Zr-O, etc. bonds could be strengthened by subsequent reduction of polarization of the trivalent ions (B3+ ions, Bi3+ ions and Mn3+ ions) in the glass system at higher concentrations of ZrO2. Photoatomic and photonuclear attenuation studies portrayed that the sample MZ0.50 has the lowest photon shielding capability. The fast neutron effective removal cross section (ΣR) was observed to be the highest for the sample MZ1.00. Thus, these glasses can be used to design the thermally stable transparent glasses, tunable optical elements, and radiation shielding materials.

Crystal structure, optical characterization, conduction and relaxation mechanisms of a new hybrid compound (C6H9N2)2[Sb2Cl8

Hybrid materials play a crucial role in the construction of flexible electronic devices due to the advantages of both organic and inorganic components. To this end, a new hybrid compound (C6H9N2)2[Sb2Cl8] was successfully fabricated using the slow evaporation solution growth approach at room temperature. In-depth research has been done on the structural, optical, and dielectric characteristics. This compound adopts the triclinic symmetry and crystallizes in the centrosymmetric space group P1̄. The inorganic and organic components respectively form anionic and cationic layers parallel to the ac-plane and alternate along the crystallographic b-axis. The [Sb2Cl8]2- dimeric units are bound to the 2-amino-5-picolinium cations [(C6H9N2)]+ through N-H⋯Cl hydrogen bonds. Optical absorption measurements showed a semiconductor behavior with a band gap of approximately 3.57 eV. In addition, DFT calculations were performed to investigate the absorption spectrum, wavelength, and HOMO-LUMO gap. The analysis of complex impedance spectra shows that the electrical conductivity of the sample is strongly frequency and temperature dependent, indicating a relaxation phenomenon and semiconductor-type behavior. Dielectric data obtained from complex impedance spectroscopy and ac conductivity with the use of the Maxwell-Wagner equivalent circuit model, and the universal power law have been investigated to explore the basic components of the electronic transport and relaxation process in our material.

Optical and Electrical Properties of Nano Magnesium Oxide Doped with Polyvinylpyrrolidone (PVP) Thin Films

A thin film of polyvinylpyrrolidone (PVP) polymer doped with different weight ratios of magnesium oxide nanoparticles produced by using the low-temperature hydrothermal method was prepared, and the morphology of the doped thin film was verified using a scanning electron microscope and an atomic force microscope. The X-ray diffraction pattern showed that magnesium oxide has a multi cubic crystal structure with a diffraction peak of high density associated with the level (200) (at the diffraction angle of 42.69◦) and a crystal drop size of 25 nm. Measurements of the Fourier A transformation of the infrared spectrum of a polyvinylpyrrolidone polymer doped with metal oxides was carried out. It showed a clear difference from the pure polymer, where a (Mg-O-Mg) bond appeared at a wavelength of 450 cm^-1 to confirm the effect of MgO addition on the chemical bonding of polyvinylpyrrolidone. Optical properties, including absorbance, maximum wavelength, and energy gap, have been studied. Determined by ultraviolet examination. The band gap decreased when MgO was doped with PVP films, and the Hall coefficient effect was used to calculate the electrical properties, including the conductivity, kinetics of charge carriers, and their type. The highest conductivity was (0.1*10^-2 Sm), and the tainted membrane was of the n type), where it can be used in optical applications.

SERS behaviors of multi-shape silver nanoparticles on Si substrate – An insight from both experimental and theoretical approaches

In this study, three types of silver nanostructures, including multi-shaped silver nanoparticles (MAgNPs), silver nanospheres (AgNSs), and triangular silver nanoparticles (TAgNPs), are developed, and their functions for surface-enhanced Raman scattering (SERS) application are investigated using both experimental and theoretical approaches. Particularly, the effects of Ag morphologies, excitation wavelength, and inter-particle gap on their SERS performance are focused. Simulation results show that MAgNPs possess a local-electric-field enhancement factor more than AgNSs (ca. 124 folds) and an electric field wider than TAgNPs. Materials characterization results show that the optimal excitation wavelengths of MAgNPs and AgNSs are in the range of 560–590 nm. Thus, employing the Raman laser source (532 nm) is highly suitable for exciting the SERS effects of Ag nanostructures in this study. For demonstrations, the MAgNPs-based SERS substrates are prepared by coating MAgNPs suspension on Si substrates. These substrates demonstrate high sensitivity to Rhodamine B (LOD of 10−13 M) with consistent reproducibility, robust durability, commendable selectivity, and impressive reusability. The results indicate that the experimental outcomes align with the theoretical simulations. These attributes collectively make the MAgNPs-based substrate a promising candidate for practical applications in Raman techniques.

Dual-channel fluorescent probe for discriminative detection of H2S and N2H4: Exploring sensing mechanism and real-time applications

A highly efficient system incorporates the real-time visualization of the two toxic molecules (H2S and N2H4) and the recognition of corresponding transforms using a fluorescent sensor. In this paper, a dual-responsive probe (QS-DNP) based on methylquinolinium-salicyaldehyde-2,4-dinitrophenyl was developed that can simultaneously detect H2S and N2H4 at two independent fluorescent channels without signal crosstalk. QS-DNP showed excellent anti-interference, high selectivity, outstanding water solubility, low LOD values (H2S: 51 nM; N2H4: 40 nM), low cytotoxicity, and mitochondrial localization properties. The 2,4-dinitrophenyl site was sensitive to H2S, and the CC bridge was reactive to N2H4, with strong fluorescence at 680 and 488 nm, respectively. The wavelength gap between these two channels is 192 nm; verify that there is no signal crosstalk throughout detection. By this means, the probe was used to simultaneously detect H2S and N2H4 in real soil samples, food samples, and living cells. The endogenous H2S and N2H4 were monitored in HeLa cells and investigated the mitochondria organelle of living cells with a positive charge on QS-DNP. Overall, all results emphasize that the QS-DNP probe is a powerful tool for the simultaneous detection of H2S and N2H4 and presents a potential new sensing approach.

Catalytic action and bactericidal behavior of samarium/carbon spheres-doped manganese oxide nanostructures and their molecular docking analysis

The co-precipitation technique was adapted to synthesize different concentrations (2 % and 4 %) of samarium (Sm) doped constant equates of carbon spheres (Cs) and manganese oxide (MnO2). The principal objective of this investigation is to demonstrate confirmation that Sm/Cs-doped MnO2 nanostructures (NSs) owned antibacterial and catalytic attributes. Reduction in surface area manifested to agglomeration, NSs faces become inaccessible to initiate a reaction, can be overcome upon doping of Sm. Sm has the potential to increase the activity of metal oxide ascribed to its electron trapping effect. The structural morphologies, optical properties, functional groups, elemental composition, and d-spacing were determined by applying various characterizations. With the incorporation of CS and Sm, UV–vis spectra shifted towards lower wavelength and band gap energy (Eg) was reduced. MnO2 possessed orthorhombic structure, according to the XRD pattern and TEM exhibited long Burr-like morphology of undoped MnO2. SAED image illustrated that MnO2 is polycrystalline. 4 % Sm/CS doped MnO2 revealed the highest degradation (91 %) in a neutral environment. Furthermore, 4 % Sm/Cs doped-MnO2 revealed an inhibitory zone of 2.85 mm against Escherichia coli (E. coli). Additionally, an analysis of molecular docking revealed a binding interface with NRs and the functional domains of certain cellular proteins. Results indicated that Cs-doped MnO2 and Cs/Sm-doped MnO2 NRs are the most potent DNA gyrase and FabB enzyme inhibitors.

Exploring linear and nonlinear optical behaviour of morpholine p-nitrophenol crystal: Computational and experimental analysis

Optically good quality morpholine p-nitrophenol (MPN) crystal was effectively grown from a slow evaporation technique. Unit cell parameters of MPN were estimated by single crystal X-ray diffraction and it crystallizes in the P21/c space group. The existence of several functional groups in MPN is established by FTIR analysis. UV–vis-NIR spectroscopy inspected the lower cut-off wavelength and band gap energy of MPN. A fluorescence spectral analysis of MPN was carried out. Experimental and computational calculations of nonlinear optical activity have been studied. The second harmonic generation of MPN is 1.9 times greater than the reference KDP material. Using the Z-scan approach, the grown crystal's third-order NLO susceptibility (χ3) was determined. The laser damage threshold of MPN crystal is studied and it is estimated as 5.12 GW/cm2. The highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) and molecular tying-up explorations were executed. Ground state enhanced geometry and molecular electrostatic potential (MEP) were analysed.

Boosting the photocathode performances of protected Cu2O inverse opals using photonic-crystal heterostructures

Cuprous oxide (Cu2O) is a highly efficient p-type semiconductor photocatalytic material with the capability for visible light absorption. In this work, three-dimensional Cu2O inverse opals with different diameters were prepared using the electrochemical deposition method. The photocathode performances were enhanced by adjusting the wavelength of photonic band gap, being co-modified by Au and Ag nanoparticles, applying the protective layers, and fabricating a photonic-crystal heterostructure with another p-type semiconductor. The slow-light effect leads a 23.9 % increase in photocurrent density. The co-modification of Au and Ag nanoparticles achieves a 77 % average increase in photocurrent density compared with pure Cu2O inverse opals. Conformal protective layers, consisting of ZnO and Al2O3 and deposited using atomic layer deposition, prevent the photocorrosion of the Cu2O photocathode while preserving its photocatalytic activity. After one hour of illumination, the photo-generated current density of protected Cu2O inverse opals is nearly three times higher than that of their uncoated counterparts. By fabricating Ag-doped ZnO with p-type characteristics and combining it with Cu2O into a heterostructure, the saturated photocurrent density of the Ag-doped ZnO/Cu2O heterostructure reaches −3.78 mA/cm2, which is almost 3.2 times higher than that of pristine Cu2O inverse opal at −0.12 V vs RHE.

Z-scan and mechanical analysis of 2-phenyl benzimidazole for optical switching application

The slow evaporation solution growth technique is used to grow single crystals of 2-phenylbenzimidazole (2PBMZ). The crystal belongs to the monoclinic system with space group C2/c, which is revealed through the single crystal XRD. The cutoff wavelength and optical band gap energy of the 2PBMZ crystal were observed at 568 nm and 1.96 ev respectively. The Vickers (Hv) hardness number, yield strength and stiffness constant are calculated, which is found to increase with the applied load. The Z-scan technique with He–Ne laser (632.8 nm) has been used to study the third-order nonlinear optical property of 2PBMZ crystal.

Study Using the Brus Equation to Examine How Quantum Confinement Energy Affects the Optical Characteristics of Cadmium Sulfide and Zinc Selenide

In this paper, the Brus equation was used to study the effects of quantum confinement energy on the optical properties of material with quantum dot (QD). It was found that the wavelength and energy gap depend on the quantum confinement energy. With the increase in the energy of quantum confinement, the energy gap increases and the absorption wavelength decreases and shifts toward the UV region. This large blue shift observed in CdS and ZnSe QDs could be exploited for the potential applications as smart materials in photonic nanodevice and various other applications.

Searching for Intragroup Light in Deep U-band Imaging of the COSMOS Field

We present the results of deep, ground based U-band imaging with the Large Binocular Telescope of the Cosmic Evolution Survey field as part of the near-UV imaging program, UVCANDELS. We utilize a seeing sorted stacking method along with night-to-night relative transparency corrections to create optimal depth and optimal resolution mosaics in the U-band, which are capable of reaching point source magnitudes of AB∼26.5 mag at 3σ. These ground-based mosaics bridge the wavelength gap between the Hubble Space Telescope WFC3 F275W and ACS F435W images and are necessary to understand galaxy assembly in the last 9–10 Gyr. We use the depth of these mosaics to search for the presence of U-band intragroup light (IGrL) beyond the local universe. Regardless of how groups are scaled and stacked, we do not detect any U-band IGrL to unprecedented U-band depths of ∼29.1–29.6 mag arcsec−2, which corresponds to an IGrL fraction of ≲1% of the total group light. This stringent upper limit suggests that IGrL does not contribute significantly to the Extragalactic Background Light at short wavelengths. Furthermore, the lack of UV IGrL observed in these stacks suggests that the atomic gas observed in the intragroup medium is likely not dense enough to trigger star formation on large scales. Future studies may detect IGrL by creating similar stacks at longer wavelengths or by pre-selecting groups which are older and/or more dynamically evolved similar to past IGrL observations of compact groups and loose groups with signs of gravitational interactions.