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In this paper, the impact on the structural, optical, morphological, and electrical properties of Zn${}_{1-x}$Co_xO, $x=0.0$, 0.02 and 0.04 nanoparticles (NPs) was investigated. Zn${}_{1-x}$Co_xO, $x=0.0$, 0.02, and 0.04 were synthesized by the thermal decomposition technique. XRD confirmed Zn${}_{1-x}$Co_xO to be hexagonal wurtzite with varying x, which represented a good incorporation of dopant ions in the ZnO lattice. Field emission scanning electron microscopy (FESEM) revealed the surface morphology of prepared ZnO NPs shaped as quasi-spherical. Energy-dispersive X-ray spectroscopy (EDS) provided the compositional information of prepared NPs having concentrations of Zn, Co, and O in the prepared NPs. Fourier transform infrared (FTIR) spectra confirm the contents of the sample, their purity, and their molecular structure. The bandgap of the NPs decreases from 3.25eV to 3.14eV with an increase of x from 0.0 to 0.04. The dielectric constant decreases with x, while the AC electrical conductivity increases with applied frequency. Recently, doped ZnO NPs have been used for the preparation of dyes, which are used for the formation of highly efficient dye-sensitized solar cells (DSSC).

The single crystals of YAG, Cr:YAG and (Cr,Ca):YAG were grown in an optical floating zone furnace. The experimental results show that the optical bandgap of the YAG, (Cr,Ca):YAG and Cr:YAG crystals is about 6.52, 6.31 and 5.50 eV, respectively. The optical bandgap of the (Cr,Ca):YAG crystal is smaller than YAG and larger than Cr:YAG. First-principles calculation results showed that the additions of Cr into YAG will give rise to the change of the electronic states. In a Cr:YAG crystal, the Cr${}^{3+}$ impurity introduces a band of 3$d$ occupied state near the Fermi level, which significantly narrowed the bandgap of Cr:YAG. In a (Cr,Ca):YAG crystal, as the Ca${}^{2+}$ ions substitute for the Y${}^{3+}$ ions, some of the Cr${}^{3+}$ ions will change into Cr${}^{4+}$ ions due to the charge balance, which increased the bandgap of the (Cr,Ca):YAG crystal in comparison with that of the Cr:YAG crystal. The calculation is in agreement with the experimental results.

Nowadays, the studies of the effects on the optical bandgap, absorption spectrum, and electrical properties of Ag–N co-doped ZnO have been extensively investigated. However, Ag and N atoms in doped systems are randomly doped, and the asymmetric structure of ZnO is yet to be explored. In this paper, the geometric structure, stability, density of states, absorption spectra and conductivity of pure and Ag–N co-doped Zn${}_{1-x}$Ag${}_x$O${}_{1-x}$N${}_x$($x$=0.03125, 0.0417 and 0.0625) in different orientations are calculated by using plane-wave ultrasoft pseudopotential on the basis of density functional theory with GGA$+$U method. Results show that the volume, equivalent total energy and formation energy of the doped system increase as the concentration of Ag–N co-doped Zn${}_{1-x}$Ag${}_x$O${}_{1-x}$N${}_x$ increases at the same doping mode. The doped systems also become unstable, and difficulty in doping. At the same concentration of Ag–N co-doped Zn${}_{1-x}$Ag${}_x$O${}_{1-x}$N${}_x$, the systems with Ag–N along the $c$-axis orientation is unstable, and doping is difficult. The optical bandgap of Ag–N co-doped systems is narrower than that of the pure ZnO. At the same doping mode, the optical bandgap of the systems with Ag–N perpendicular to the $c$-axis orientation becomes narrow as the concentration of Ag–N co-doped Zn${}_{1-x}$Ag${}_x$O${}_{1-x}$N${}_x$ increases. The absorption spectra of the doped systems exhibit a red shift, and this red shift becomes increasingly significant as the concentration of Ag–N co-doped Zn${}_{1-x}$Ag${}_x$O${}_{1-x}$N${}_x$ increases. Under the same condition, the relative hole concentrations of the doped systems increases, the hole effective mass in valence band maximum decreases, the hole mobility decreases, the ionization energy decreases, Bohr radius increases, the conductance increases and the conductivity become better. Our results may be used as a basis for the designing and preparation of new optical and electrical materials for Ag–N co-doped ZnO applied in low temperature end of temperature difference battery.

Y-type hexagonal ferrite (CaBaCo₂Ga${}_{0.5}$Fe${}_{11.5}$O${}_{22}$) was synthesized by sol–gel technique. The ferrite–polymer composites (1−x)CaBaCo₂Ga${}_{0.5}$Fe${}_{11.5}$O${}_{22}$+(x)polyaniline (x=0.25, 0.50, 0.75, 1) namely PF1, PF2, PF3 and polyaniline (PANI) were synthesized by in situ polymerization. The synthesized samples were characterized by XRD, SEM, electrical and dielectric measurements, optical and magnetic studies. XRD pattern reveals a broad peak of polyaniline which is an indication of amorphous nature of PANI. Room-temperature resistivity increases from 2.14 × 10¹ $\mathrm{\Omega }\cdot$cm to 2.78 × 10${}^{10}\mathrm{\Omega }\cdot$cm as ferrite content increases due to resistive behavior of the ferrite particles dispersed in the PANI matrix. The value of dielectric constant decreases at fixed frequency with increasing concentration of ferrite filler which is predominantly due to exchange of electrons between Fe${}^{+2}$ and Fe${}^{+3}$ ions that ultimately results in enhancement of electric polarization and conductivity. The optical bandgap increases with increasing amount of ferrite in the composites. The saturation magnetization and remanence increase with the increase of ferrite filler amount in PANI matrix whereas coercivity decreases. The decrease in coercivity and increase in saturation magnetization are related to Brown’s relation. The present nanocomposite samples may be the best candidates for electromagnetic shielding.

Titanium (${\mathrm{\text{Ti}}}^{4+}$)-doped nanoparticles of the type ${\mathrm{\text{Zn}}}_{0.94}{\mathrm{\text{Cd}}}_{0.06-x}{\mathrm{\text{Ti}}}_x\mathrm{\text{O}}$ [$x=0.0$, $0.03$] are reported in this study. The samples were synthesized by citric acid assisted sol–gel auto combustion (SGAC) method. The samples are characterized by X-ray diffraction (XRD), Raman, Field emission scanning electron microscopy (FESEM), Energy dispersive analysis of X-rays (EDAX) and Fourier transform infra-red (FTIR) techniques for structural studies. Further, for optical properties, UV-Vis technique has been used. In addition, samples were studied for dielectric properties. Room-temperature XRD data study reveals the sample formation with wurtzite hexagonal structure exhibiting space group $P{6}_3$mc also confirmed from Rietveld refinement of XRD data. Raman spectra displays characteristic active phonon modes in pristine ${\mathrm{\text{Zn}}}_{0.94}{\mathrm{\text{Cd}}}_{0.06}\mathrm{\text{O}}$ and doped ${\mathrm{\text{Zn}}}_{0.94}{\mathrm{\text{Cd}}}_{0.03}{\mathrm{\text{Ti}}}_{0.03}\mathrm{\text{O}}$. UV-Vis diffused reflectance spectroscopy analysis infer bandgap values of 3.14 and 3.12 eV for ${\mathrm{\text{Zn}}}_{0.94}{\mathrm{\text{Cd}}}_{0.06}\mathrm{\text{O}}$ and ${\mathrm{\text{Zn}}}_{0.94}{\mathrm{\text{Cd}}}_{0.03}{\mathrm{\text{Ti}}}_{0.03}\mathrm{\text{O}}$, respectively. The dielectric studies confirmed high dielectric constant for ${\mathrm{\text{Zn}}}_{0.94}{\mathrm{\text{Cd}}}_{0.03}{\mathrm{\text{Ti}}}_{0.03}\mathrm{\text{O}}$ compared to pristine ${\mathrm{\text{Zn}}}_{0.94}{\mathrm{\text{Cd}}}_{0.06}\mathrm{\text{O}}$. A non-Debye character with spread of relaxation times was witnessed from impedance study.

In this work, we discuss the synthesis, characterization and dielectric properties of Bi${}_{0.9}$La${}_{0.1-x}$(Ba/Sr)${}_x$FeO₃ [$x=0,0.05$] ceramic compounds. These samples were synthesized via a solid-state reaction method and then characterized for structural analysis exploiting the X-ray diffraction (XRD) technique. The Rietveld refinement data inferred that all the prepared samples were acquired a monoclinic phase with space group C1c1. Field emission scanning electron micrographs (FE-SEM) images of the samples indicated highly grown grains with a moderate level of grain boundary development across the sample. The energy dispersive analysis of the X-ray (EDAX) diffraction spectra analysis confirmed that the composition was free from foreign impurities. Further, UV–Vis experiment was conducted and estimated average value of optical bandgap was about 2.2 eV, which is highly recommended for photocatalytic and opto-electronic device applications. Room-temperature dielectric studies revealed that samples were extremely good dielectric materials with low dielectric loss, which is important for storage device applications. In addition, the depressed semicircles obtained from impedance analysis indicated that the samples exhibited distributed relaxation times and non-Debye behavior.

The characteristics of nip-type a-Si:H thin film solar cells based on DNA-CTMA biopolymer was investigated. The DNA-CTMA was used as the buffer layer in nip-type a-Si:H solar cell. The E_opt of the DNA-CTMA biopolymer was measured with UV-VIS spectrometer. The E_opt of DNA-CTMA was determined as 3.96 eV by the plot of (Ahν)² versus hν. All films of amorphous materials were deposited by PECVD method. The solar cell with a simple structure of glass/ITO/n-a-Si:H/i-a-Si:H/p-a-Si:H/DNA-CTMA/Al was fabricated. The various values of V_oc, J_sc, FF, and conversion efficiency η were measured under 100 mW/cm² (AM 1.5) solar simulator irradiation. Consequently, the resulting in solar cell showed an enhancement in conversion efficiency η compared to conventional nip-type a-Si:H solar cell without buffer layer of DNA-CTMA biopolymer.

In this paper, effect of oxygen (O${}^{+}$) ion irradiation on the properties of polycrystalline cubic structure CdTe thin films has been investigated. CdTe thin films were irradiated with O${}^{+}$ ions of energy 80keV at different fluence ranging from $1\times 10^{15}$ to $5\times 10^{16}$ion/cm² at room temperature. At $1\times 10^{15}$ion/cm² O${}^{+}$ ions fluence, the CdTe structure was maintained while XRD peaks of cubic phase were shifted toward lower angles. At $5\times 10^{16}$ion/cm² O${}^{+}$ ions fluence, cubic structure of CdTe thin films was transformed into hexagonal structure. In addition, electrical resistivity and optical bandgap were decreased with increasing O${}^{+}$ ion beam irradiation.

The effect of substrate temperature on growth of pulsed laser deposited copper oxide thin films has been investigated by employing Nd: YAG laser (532nm, 6ns, 10Hz) irradiation at a fluence of 8.2J/cm². XRD analysis reveals that copper oxide films deposited at room temperature are amorphous in nature, whereas films deposited at higher substrate temperatures are polycrystalline in nature. SEM and AFM analyses revealed that films deposited at substrate temperatures, ranging from room temperature to 300${}^{\circ }$C are comprised of large sized clusters, islands and particulates, whereas uniform films with an appearance of granular morphology and distinct bump formation are grown at higher substrate temperatures of 400${}^{\circ }$C and 500${}^{\circ }$C. The optical bandgap of deposited films is evaluated by UV-VIS spectroscopy and shows a decreasing trend with increasing substrate temperature. Four point probe analysis reveals that electrical conductivity of the deposited films increases with increase in the substrate temperature, and is maximum for highest growth temperature of 500${}^{\circ }$C. It is revealed that growth temperature plays a significant role for structure, texture, optical and electrical behavior of copper oxide thin films. The surface and structural properties of the deposited films are well correlated with their electrical and optical response.

This investigation aimed to explore the characteristics of reduced graphene oxide (rGO) through a comprehensive approach. The synthesis of graphene oxide (GO) began with a customized adaptation of the modified Hummer’s method, followed by subsequent chemical and thermal reduction processes. Chemical reduction involved the use of ascorbic acid, hydrazine hydrate, and sodium borohydride, while thermal reduction occurred at various temperatures in the presence of hydrogen. The study employed a diverse array of analytical techniques to unravel the structural and chemical intricacies of the material. X-ray diffraction (XRD) revealed significant changes indicative of structural transformations. Raman spectroscopy meticulously examined defects and layer formations. Scanning Electron Microscopy (SEM) visualized the evolutionary aspects of the material’s structure. UV–VIS spectroscopy is employed to analyze the optical bandgap of the sample, and the primary importance of this study lies in its application potential for solar cells.

Reclusive single crystals of ammonium dihydrogen phosphate (ADP) and 0.1mol.% Acid Blue 22 dye-incorporated ADP were harvested by using a standard slow cooling mechanism. The skeletal framework of the anisotropic materials was analyzed by using single crystal X-ray diffraction cram. The powder X-ray diffraction examines the phase growth and incorporation of substituents in the crystalline matrices. The incorporation of additives in the system was examined by employing Fourier Transform Infrared Spectroscopy. The analysis of vibrational bands gives insights into the incorporation of additives in ADP crystal system. The transmission window of the specimen and optical bandgap of the given material were analyzed by using UV–Vis spectroscopic analysis. The incorporation of additives to parent crystals was examined by using Scanning Electron Microscope. The quantification of elements in the grown specimen was investigated by using Energy Dispersive X-ray spectroscopy. The mechanical rigidity of the material was inspected by using Vickers microhardness analysis. The piezoelectric charge coefficient of dye-incorporated ADP is higher than pristine ADP. The wettability of the material was identified by contact angle measurements. The optical stress was identified by employing photoelastic measurements. The second- and third-order nonlinear optical properties of pristine and dye-incorporated ADP crystals were investigated by using Kurtz–Perry powder technique and Z-scan technique.

Global reactivity descriptors, Milliken’s charge distribution and molecular electrostatic potential based on Density Functional Theory (DFT), are used to understand the relationship between structure, stability and global chemical reactivity. In addition, these descriptors are used in the development of quantitative structure-activity and structure-property relationships. The study also shows the intense effect of the chlorine atom in the charge distribution. X-ray pattern reveals the crystalline structure along the (242) orientation of Aluminum Chloride phthalocyanine (AlCl-Pc) organic thin layer. Absorbance of such layer exhibits a high value within UV range and two consecutive peaks within visible range, spin coating is used to make an organic diode based on the AlCl-Pc cluster and the diode high rectifying facility is discovered. The height barrier is constant and saturation current is greatly reliant on light, the ideality factor of such a diode increases to 6.9 which confirms the non-ideality of such device.