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The present work reports Cd 1-x Zn x S (x = 0.0, 1.0, 3.0 and 5.0 wt%) nanostructured thin films growth on glass substrates via spray pyrolysis technique. As grown films exhibited hexagonal wurtzite structure with preferred orientation along (002) plane. The optical band gaps of the samples were obtained in the range ∼2.41–2.45 eV. The incorporations of 5.0 wt% Zn in CdS matrix revealed a significant widening in the band gap of the films. In addition, the films nonlinear optical properties were also improved with Zn doping in the CdS system. The films optoelectronics parameters such as response, recovery time, and detectivity were measured as functions of Zn doping concentrations. The prepared films revealed a remarkable visible light photodetection that is improved with the increasing Zn doping concentrations. The optoelectronic parameters such as external quantum efficiency (EQE), detectivity (D*) and responsivity (R) were obtained and found in the order of ∼0.48–553, 1 × 109–1 × 1011 Jones and 0.15–1.72 A/W, respectively. The obtained results demonstrate the superior performance of the Cd 1-x Zn x S system and its high suitability for advanced optoelectronic applications. • High quality Cd 1-x Zn x S nanocrystalline thin films with different Zn doping concentrations grown by spray pyrolysis method. • Band gap of thin films varies significantly with Zn doping concentration in CdS matrix. • Substantial improvement shows in visible light photodetection with the increase in Zn doping concentrations. [ABSTRACT FROM AUTHOR]

Graphical abstract Variation of sheet resistance of silver nanowires based hybrid conductive electrodes under continuous applied bias. Interconnecting silver nanowires with conductive polymer wrapped carbon nanotubes significantly improves the electrical stability of electrode and helps to overcome the failure issue of silver nanowires network. Highlights • A novel method to improve the electrical stability of silver nanowires network electrodes is reported. • The conductive polymer wrapped CNTs were used to interconnect the individual NWs and to produce electrically robust conductive hybrid electrode. • The hybrid electrode with modified carbon nanotubes shows highly stable electrical performance in comparison with silver nanowires electrode. Abstract Silver nanowires have high potential to replace the conventional transparent conductors in many applications. However, the electrical instability of silver nanowires especially when heated as a result of electrical current passage causes the failure of this type of conductors and thus may limit their uses in many applications. In this study, a novel approach based on interconnecting the individual nanowires with conductive polymer wrapped carbon nanotubes is examined to improve the stability of silver nanowires network. The hybrid electrode with modified carbon nanotubes shows highly stable electrical performance in comparison to silver nanowires electrode. Under continuous electrical stress, slight variation in the sheet resistance of the hybrid electrode was noticed and was about two order of magnitude less than that of silver nanowires electrode. Moreover, the thermal studies reveal that the hybrid electrode stabilizes at much lower temperature than that of silver nanowires electrode. The findings show that the proposed approach is very promising to overcome the failure issue of silver nanowires and to increase the feasibility of their use for device applications. [ABSTRACT FROM AUTHOR]

We report here the FTIR, optical, and magnetic properties of Sn 1-x-y Zn x M y O z ceramics with various x, y, and M. The pure samples are called S1, S2, and S3 for ZnO, SnO 2 , and SnZn. The co-substituted samples are called S4, S5, S6, and S7 for SnZnFe, SnZnCo, SnZnNi, and SnZnMn, with Zn = 0.50, Sn = 0.25, and M = 0.25. The Young's modulus, was decreased from 5.70 (D/cm2) for S3 to 4.59, 3.14, 2.59, and 3.05 (D/cm2) for S4, S5, S6, and S7. The E g was decreased from 2.13 eV for S3 to 2.16, 2,2, and 1.6 eV for S4, S5, S6, and S7. The pure samples (S1–S3) exhibit ferromagnetic behavior at 300 K, and combination of paramagnetic and ferromagnetic behaviors at 10K. In contrast, the samples (S4–S7) exhibit a combination of paramagnetic and ferromagnetic behaviours at both temperatures. The Curie temperature (T c) obtained through zero-field cooling (ZFC) and field cooling (FC) is close to 300 K for S1–S3, S5, S6, 200 K for S4, and 20 K for S7. The real saturated magnetization (M s) of the ZnO sample was decreased by the addition of SnO 2 , and then increased by the addition of Mn, Ni, Fe, and Co sequentially. M s was increased from 12.31 (emu/g) for S3 at 300 to 16.24, 31.04, 27.27, and 10.49 (emu/g) for S4, S5, S6, and S7, and from 16 (emu/g) to 87, 730, 83, and 29 at 10 K. Remnant magnetization (M r) decreases with the addition of SnO 2 to ZnO and is not affected by the addition of TMs, just in the case of Co, where it increases. The coercive field decreases, but the switching field increases markedly with the addition of Mn and Ni, transforming the system from a hard magnetization to a soft magnetization system. [ABSTRACT FROM AUTHOR]

[Display omitted] • UV detection of nanostructure thin films was analyzed in correlation of grain size of films. • UV detection of nanostructure thin films was analyzed in correlation of grain size of films. • Optoelectronic performance of films considerably dependence on rpm. Here we report on the development of ZnO nanostructured thin films-based UV detectors, fabricated via cost effective sol–gel spin coating method. The prepared films possess hexagonal wurtzite structure with strong texturing along the [0 0 2] directions. Morphological studies of the films confirm the formation of nano-sized granular structures. It was found that the UV detection performance of these nanostructured films is decreased spectacularly, about thirty-fold, by reducing the grains size from 23 nm (at 1500 rpm) to about 11 nm (at 3000 rpm). The grain sizes and optical band gaps of the films were found to considerably vary with the rpm. In addition to the high UV detection performance, the prepared films show about 85–90% optical transmittance in the visible region of the solar spectrum. Our study provides a cost-effective approach for performance improvements of ZnO nanostructures based optoelectronic devices. [ABSTRACT FROM AUTHOR]

ZnTiO 3 nanoparticles (NPS), synthesized using a sol-gel process from zinc acetate dihydrate and titanium tetrabutanolate, were incorporated into aluminum borosilicate glasses to enhance their effectiveness in water purification. Integrating ZnTiO 3 -NPS at the expense of SiO 2 causes significant alterations by converting [BO 3 ] to [BO 4 ], modifying the Si-O bonds with other metal oxides, and creating a denser structure with more bridging oxygens. The structural improvement is indicated by higher ultrasonic velocities and elastic moduli, demonstrating a stronger and more unified glass framework. The study investigates how different concentrations of ZnTiO 3 -NPS affect the glasses' structure and mechanical and optical properties, specifically observing changes in light transmission, such as a blueshift in the absorption edge towards longer wavelengths. This blueshift due to ZnTiO 3 -NPS was assured by the observed decrease in the optical band gap (E g) values and the increase in the mean oscillator position (λ o) values. Furthermore, the real (σ r) and imaginary (σ i) parts of the optical conductivity, nonlinear optical parameters viz. first (χ(1)) and third (χ(3)) orders subsatellites, and nonlinear index of refraction (n 2) have been estimated based on the values of the linear index of refraction (n) and the extinction coefficient (k). The optical modifications impact the refractive index, suggesting various potential technological applications based on the ZnTiO 3 levels. [ABSTRACT FROM AUTHOR]

In this work, we report a theoretical investigation of the structural, electronic and optical properties of Cd 1 − x Ag x S alloys with a wurtzite structure. The calculations were performed using the density functional theory (DFT). The full potential linearized augmented plane wave (FPLAPW) scheme, implemented in Wien2k package, was employed. The modified Becke–Johnson potential with generalized gradient approximation (mBJGGA), which combines the Becke–Johnson exchange potential with the generalized gradient approximation correlation potential, was used to evaluate the alloys band structure. The study was carried out for the composition of silver x = 0 , 0.027, and 0.055. The obtained band structures and the density of states of these alloys revel that by increasing the silver composition in CdS matrix, the Fermi level cross the E(k) curves in the majority-spin states showing a metallic behavior. While the minority-spin state is semiconducting. A band gap channel was observed between the spin up and spin down level giving rise to a half metallic behavior. The origin of this bandgap is attributed to the silver d-band hybridization. The optical properties were also investigated and were found to be deeply affected by the silver composition. The optical absorption is gradually shifted to the lower energy and the compound becomes more absorbent in the infrared region. The structural and optoelectronic proprieties of the half metal Ag-doped CdS materials, were investigated and are presented in the current study and discussed in details. The findings of the study show that Cd 1 − x Ag x S alloys with their spin-based properties could pave the way for many novel optoelectronic devices in addition to spintronics applications. [Display omitted] • A decrease in the lattice parameters occurs after the substitution of Cd with Ag atoms in the CdAgS supercell. • The density of states shows a strong hybridization of the d states of Ag and the p orbitals of S near the Fermi level. • A transition from semi-metal to metal character of CdAgS occurs by increasing the silver composition. • The peaks of the dielectric function imaginary part in the lower energy region move to the infrared spectrum with the silver composition. • The Ag-doped CdS alloys clearly show novel electronic properties for optoelectronic applications. [ABSTRACT FROM AUTHOR]

• Excimer laser sintering of printed Ag nanoparticles electrodes was investigated. • Sintering process parameters were optimized to produce highly conductive electrodes. • The laser sintered Ag electrodes were utilized to fabricate high performance OTFTs. • Excimer laser is a promising alternative tool for metallic nanoparticles sintering. Printing and related processing technologies of electronic materials have become an essential part in the production of many components of today's electronics. Laser processing of metal based inks in particular has received a great attention and can eliminate the need of the conventional high temperature sintering methods. Here, silver nanoparticles ink was printed using a drop on demand (DOD) printer and cured to produce highly conductive silver patterns. The printed silver nanoparticles were sintered using excimer laser and thermal treatment. The effects of curing parameters such as energy density, scan speed and annealing temperature on the surface morphology and electrical performance of the inkjet printed structures were investigated. The results revealed strong dependence of the morphology and electrical performance of the printed samples on the process parameters namely the laser fluence and the scanning speed. The production of discontinuous samples and laser ablation of silver sintered patterns at some treatment stages were also noticed. Moreover, using optimized sintering conditions, highly conductive patterns similar to those thermally treated were produced. The printed conductive patterns were then successfully utilized as S/D electrodes for organic thin film transistors. The fully solution processed transistors with printed silver electrodes exhibited excellent ohmic contact characteristics with mobility and on/off ratio in the range of 10−2 cm2/V·s and 103, respectively. The results indicate that, in addition to the various material processing uses, excimer laser can also be used as a sintering tool for printed metallic nanoparticles in the roll-to-roll manufacturing processes. [ABSTRACT FROM AUTHOR]

In this paper, various fully solution-processed top-gate bottom contacts organic thin-film transistors based on printed silver nanoparticles electrodes were fabricated, electrically characterized, and analytically modeled. The performance of the designed devices thermally and laser sintered nanoparticles electrodes was investigated. The device based on electrode sintered thermally exhibits improved contacts with an on/off ratio of 1.6 × 103 and a saturation mobility of 1.23 × 10−2 cm2V−1s−1. The current–voltage characteristics of OTFTs in terms of the transfer and output characteristics were also modeled and reproduced using an analytical model. Furthermore, various effects were considered in the used model, including the channel length modulation and contact resistance effects as well as field-effect mobility dependence of the gate voltage. The proposed model results for the devices were found to be in a good agreement with the experimental data in terms of the transfer and output characteristics. It was found that the used analytical model correctly describes the electrical characteristics, and it is proved to be accurate enough to explain the charge transport in these types of OTFTs. The development of such model will certainly help in the design of high-performance nanomaterials based OTFTs and their future advancement as well. • Fully solution-processed OTFTs based on thermally and optically treated silver nanoparticles electrodes were characterized and modeled. • The fabricated OTFTs show high performance suitable for flexible and printed electronics applications. • The results of the proposed model show good agreement with the experimental data. • The proposed model can be utilized to optimize the performance of OTFTs and improve it further. [ABSTRACT FROM AUTHOR]

[Display omitted] • Adsorption of methylene blue dye on functionalized nano-adsorbents was investigated. • New insights into MB adsorption over these nano-adsorbents are reported. • Isotherm modeling using statistical physics and traditional equations are reported. • Dye adsorption process was monolayer via physisorption involving van der Waals forces and hydrogen bonding. • CIS/ZnS nano-adsorbent exhibited high adsorption and photocatalytic capacity for MB degradation. Copper indium sulfide (CIS), zinc sulfide (ZnS) and CIS/ZnS nano-adsorbents (NAs) encapsulated with mercaptopropionic acid (MPA) were synthesized and characterized with different techniques, and finally tested for the adsorption/photodegradation of methyl blue dye (MB) in aqueous solution under UV irradiation. Structural and optical properties of the nanocrystals were determined via Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Transmission electron microscopic, UV–Visible and photoluminescence spectroscopy. CIS/ZnS showed a specific surface area of 24.06 cm2 g−1 and an adsorption capacity of 27.71 mg g−1 for MB. MB adsorption kinetic was found to follow the pseudo-second order kinetic model and the Langmuir-Freundlich model was the best model to describe the adsorption isotherms. Taking into account the statistical physics analysis and the theoretical meaning of the parameters, the Hill model with one activation energy presented the best prediction of the experimental data, indicating that MB dye adsorption occurred by the formation of a monolayer and that MB interaction with CIS/ZnS were characterized by only one activation energy. The calculated adsorption energy varied from 19.38 to 20.04 kJ mol−1 suggesting that the adsorption occurred via physical interactions via a multimolecular adsorption process. The photodegradation activity of the core–shell NAs under UV irradiation showed better efficiency than the bare core and Shell NAs thus indicating that ZnS recovery improved the degradation power of the CIS nano-adsorbents (97 %). In summary, these eco-friendly NAs are highly promising materials for efficient wastewater treatment to face water pollution caused by organic compounds via adsorption and photodegradation processes. [ABSTRACT FROM AUTHOR]

The decomposition of GaN layers have been in situ monitored by a spectral reflectance system. A particular interest is given to the early stages of GaN decomposition. The analysis of the spectral reflectance behavior shows a rapid reflectance increase, which is associated with the formation of gallium metallic layer. After that, reflectance oscillates and damps with the processing time indicating the decomposition of the GaN layer. The transfer matrix formalism and the effective refractive index concept have been combined to understand the experimental recorded reflectance responses during GaN decomposition under H 2 flux at high temperature. We have developed an effective refractive index formula taking into account the coexistence of gallium and GaN materials for fitting experimental results. This assumption has been validated as a good tool for the interpretation of the reflectance variations. Our results are confirmed and analyzed based on scanning electron microscopic (SEM) observations and photoluminescence measurements. • GaN layers were thermally decomposed under H 2 ambient gaz. • The decomposition process was in situ monitored by spectral reflectance system. • Gallium metallic layer was formed during the early stages of GaN decomposition. • A theoretical model was developed to reproduce experimental reflectance spectra. [ABSTRACT FROM AUTHOR]

In the current study, we investigated the partial decomposition of GaN layers grown on SiN-treated sapphire substrate in an atmospheric pressure metal organic vapor phase epitaxy (AP-MOVPE) vertical reactor under N 2 ambient at 1200 °C. Under these experimental conditions, we studied the decomposition of different coalescence degrees GaN layers and the early thermal decomposition stages of GaN films. By the help of the scanning electron microscope (SEM), the surface morphology of the decomposed GaN epilayers was examined. We demonstrated that the thermal decomposition leads to an irregular etching process, which was carried out step by step. The optical properties of the decomposed films were then studied by using the photoreflectance (PR) technique at room temperature and at 11 K. We determined a logarithmic relation between the built-in electric field in the surface of GaN layers and the stress value. A model is also proposed to extract the stress value from PR spectra. It should be noted also that by using the thermal decomposition process, the stress inside GaN layers can be reduced by a factor of 6. [ABSTRACT FROM AUTHOR]