Ag Doping Research Articles

Reducing carrier recombination loss by suppressing Sn loss and defect formation via Ag doping in Cu2ZnSn(S,Se)4 solar cells

The position of Ag of the CZTSSe precursor significantly impacts the carrier recombination loss and overall efficiency, offering crucial insights for optimizing the CZTSSe solar cell design.

High-pressure effects on the electronic properties and photoluminescence of Ag-doped CsCu2I3.

CsCu2I3 is a popular lead-free metal halide perovskite with good thermal and air stability. To facilitate its applications in optoelectronics, Ag doping and high pressure are employed in this work to improve the optoelectronic properties of CsCu2I3. Using first-principles calculations and experiments, the structural phase change of 10% Ag-doped CsCu2I3 is found to occur at about 4.0 GPa. This reveals the regulation of band structures by hydrostatic pressure. In addition, the high pressure not only increases the emission energy of photoluminescence of 10% Ag-doped CsCu2I3 by more than 0.2 eV, but also increases the emission intensity by multiple times. Finally, the origin of luminescence in 10% Ag-doped CsCu2I3 is attributed to the I vacancies. This work provides insight into the structure and optoelectronic properties of 10% Ag-doped CsCu2I3, and offers significant guidance for the design and manufacturing of future luminescence devices.

Synthesis of RhH-doped Au-Ag alloy nanoclusters and dopant evolution.

Doping atomically precise metal nanoclusters (NCs) with heterometals is a powerful method for tuning the physicochemical properties of the original NCs at the atomic level. While the heterometals incorporated into metal NCs are limited to group 10-12 metals with closed d-shells, the doping of open d-shell metals remains largely unexplored. Herein, we report the synthesis of Rh-doped Au-Ag alloy NCs by a metal-exchange reaction of [RhHAg24(SPhMe2)18]2- NCs with an Au-thiolate complex. Combined experimental and theoretical structural studies revealed that the synthesized product is a dianionic [RhHAuxAg24-x(SPhMe2)18]2- NC (x = 8-12), consisting of RhH dopant, Au-rich kernel, and Ag-thiolate staple motifs, with the superatomic 8-electron configuration (1S21P6). Under aerobic conditions, the synthesized NCs underwent kernel evolution to generate a 6-electron [RhAuxAg24-x(SPhMe2)18]1- NC (1S21P4), which was initiated by the desorption of hydride from the kernel. Structural analysis of the [RhHAuxAg24-x(SPhMe2)18]2- NC suggests that the kernel evolution is induced by the change in chemical bonds surrounding the hydride in the Au-rich kernel.

A combined experimental and modelling approach for the evaluation of the thermoelectric properties of Ag-doped SnS

We report for the first time a combined computational and experimental study of the impact of Ag doping on the thermoelectric properties of SnS and introduce a fitting procedure to determine parameters that cannot easily be determined experimentally.

CaTiO3: Influence of Ag Doping on Photocatalytic Activity for Application in Rhodamine B dye Removal

CaTiO3: Influence of Ag Doping on Photocatalytic Activity for Application in Rhodamine B dye Removal

Enhanced gas sensing performance of Ag-Doped BiFeO3 microspheres synthesized via flash auto combustion technology

This investigation demonstrates the successful synthesis of well-crystallized pristine and Ag-doped BiFeO3 microspheres using flash auto combustion technology. The effects of Ag doping on the morphology and microstructural characteristics were thoroughly examined through SEM, EDS, and powder X-ray diffraction (XRD) studies. Gas sensing experiments were performed to evaluate the response of the synthesized materials to NO gas. The results revealed a remarkable enhancement in the gas sensing capabilities of 5% wt Ag-doped BiFeO3 compared to pure BiFeO3. Specifically, the gas response towards NO was found to be 2.4 times higher for Ag-doped BiFeO3. This significant improvement can be attributed to the presence of Ag atoms within the lattice structure, which not only increased the density of holes in the material but also created additional gas molecule adsorption sites. Furthermore, the Ag dopant exhibited a catalytic effect, contributing to the excellent gas sensor performance of the material. These findings hold great promise for the development of highly sensitive and efficient gas sensors, particularly in applications where the detection of low concentrations of NO is crucial. The utilization of flash auto combustion technology in the synthesis process offers a viable route for scalable production of advanced gas sensing materials with enhanced performance.

Unraveling the impact of Ag dopant in Zn–In–S colloidal nanocrystals for boosting visible-light-driven photocatalytic CO2 reduction

Ag doped Zn–In–S colloidal nanocrystals.

Defect Induced high-color-rendering white light emissions from Ag-doped ZnO

It is crucial to find high-quality white-light phosphors that are simple to synthesize in order to create efficient lighting. In this pursuit, the focus has been on achieving the emission of white light in ZnO and Ag-doped ZnO emerging as a promising phosphor candidate. The optimized ZnO nano phosphors demonstrated visible-light emission with ideal Commission international de I E “Eclairage frequently abbreviated as coordinates (x = 0.33, y = 0.33 ) and a correlated color temperature of 6200 K, and a color rendering index of 100 for equivalent to day white light. Furthermore, under certain ideal processing conditions, neutral white-light emission (x = 0.33, y = 0.33 at λex = 280 and 370 nm) with a Color correlated temperature (CCT) of 5500 K(approx.) was achieved. The Color Rendering Index (CRI) of the ZnO and Ag:ZnO nanoparticles exceeded 90, with high values approaching 96%, which is necessary for accurately portraying object colors in comparison to natural sunshine. The research findings revealed a decrease in the FS emission intensity with all the UV excitation when Ag doped in ZnO, which aligns well with the principles of Stern-Volmer quenching. A reduction in intensity was observed which may be due to the Ag dopant interacting with the luminescent nanoparticles and causing a reduction in their emitted light. The study successfully develops and optimizes ZnO-based nano phosphors with tailored white-light emission characteristics, presenting a promising solution for achieving energy-efficient and high-quality white-light sources for various lighting applications.

Defect Engineering of Metal Halide Perovskite Nanocrystals via Spontaneous Diffusion of Ag Nanocrystals.

Perovskite nanocrystals (NCs) have emerged as a promising building block for the fabrication of optic-/optoelectronic-/electronic devices owing to their superior characteristics, such as high absorption coefficient, rapid ion mobilities, and tunable energy levels. However, their low structural stability and poor surface passivation have restricted their application to next-generation devices. Herein, a drug delivery system (DDS)-inspired post-treatment strategy is reported for improving their structural stability by doping of Ag into CsPbBr3 (CPB) perovskite NCs; delivery to damaged sites can promote their structural recovery slowly and uniformly, averting the permanent loss of their intrinsic characteristics. Ag NCs are designed through surface-chemistry tuning and structural engineering to enable their circulation in CPB NC dispersions, followed by their delivery to the CPB NC surface, defect-site recovery, and defect prevention. The perovskite-structure healing process through the DDS-type process (with Ag NCs as the drug) is analyzed by a combination of theoretical calculations (with density functional theory) and experimental analyses. The proposed DDS-inspired healing strategy significantly enhances the optical properties and stability of perovskite NCs, enabling the fabrication of white light-emitting diodes.

Elevating superpacitor performance: Enhancing electrochemical efficiency with transition metal-doped polyaniline electrode

Polyaniline (PANI) stands out as a highly favored electrically conductive polymer, extensively investigated for its potential as an electrode material in the advancement of energy storage systems. Nevertheless, the practical utilization of PANI is hindered by its inadequate stability, posing limitations on its wider application. To address this issue, doping with carbon and carbon-based materials or transition metals is frequently employed. In this study, transition metals Ag+ and Fe3+ were doped into the of polyaniline PANI structure to enhance its surface area, conductivity, and electrochemical properties. The doping of Ag+ and Fe3+ into the PANI structure resulted in a significant increase of up to three times in the surface area and conductivity of PANI. Electro-Paramagnetic Resonance (EPR) spectra analysis showed a substantial change in the intensity value with Ag+ doping, while no significant alteration was observed in the g-factor values. Electrochemical analyses demonstrated that both Ag+ and Fe3+ doping improved the specific capacitance, energy density, and power density of PANI in both symmetric and asymmetric designs. Furthermore, the utilization of electron paramagnetic resonance (EPR) spectroscopy complemented the comprehensive electrochemical analysis by offering valuable insights into the defect structures present in the electrode materials.

Photocatalytic degradation of ciprofloxacin drug utilizing novel PVDF/polyaniline/ lanthanum strontium manganate@Ag composites

Poly (vinylidene fluoride) (PVDF) is the first-choice ferroelectric support or membrane material. The lanthanum strontium manganite (LSMO) is a well-known electrode material in the class of the solid oxide fuel cell (SOFC) materials. A set of four polymer composites PVDF-LSMO-PANI(5.0 wt%) with different amount of silver doping were fabricated with the silver nitrate and reducing agent. The characterization of these four novel PVDF based composites were characterized by the XRD, FTIR, SEM, UV-Visible DRS. The present communication highlights: (I) the effect of PANI in the PVDF-LSMO-PANI (PLP) composites towards the photocatalytic degradation of ciprofloxacin drug. (II) the effect of Ag doping in the Ag-PVDF-LSMO-PANI (Ag-PLP) composites towards the photocatalytic degradation of ciprofloxacin drug. It is observed that the incorporation of PANI in PVDF-LSMO and Ag in PVDF-LSMO-PANI polymer ceramic composites showed enhanced photocatalytic degradation of ciprofloxacin in the irradiation of visible radiation. The plausible separation of photo-generated e- hole pairs (e- and h+) carried on by charge migration kind of mechanism is being studied here to understand the improved photocatalytic activity of Ag-PVDF-LSMO-PANI composites.

Tuning electronic properties of hydroxyapatite through controlled doping using zinc, silver, and praseodymium: A density of states and experimental study

This study presents a comprehensive exploration of the electronic properties of hydroxyapatite (HA) doped with zinc (Zn), silver (Ag), and praseodymium (Pr). Five distinct compositions—0.4Pr-HA, 0.4Zn-0.4Pr-HA, 0.8Zn-0.4Pr-HA, 0.4Ag-0.4Pr-HA, and 0.8Zn-0.4Pr-HA were systematically investigated through Density of States (DOS) and band structure calculations. The computed band gap values, ranging from 4.4037 to 4.1554 eV, revealed a progressive decrease in band gap energy from 0.4Pr-HA to 0.8Ag-0.4Pr-HA, emphasizing the substantial impact of dopant composition on electronic properties. Additionally, the incorporation of Pr induced distinct bands and peaks in the density of states, signifying the emergence of specific energy levels associated with Pr and suggesting a clear effect on the electronic structure. Furthermore, the study explores the influences of dopant type and quantity on the electronic structure, microstructure, spectral, thermal, and in vitro cell viability properties of Pr-based HA samples. Theoretical results demonstrated a continuous decrease in the bandgap with Ag or Zn dopants, and the study observed controllable changes in LAC values based on co-dopant type and quantity. Experimental outcomes revealed significant effects on crystallinity, crystallite size, lattice parameters, and unit cell volume, confirmed through XRD, SEM, EDX, FTIR, and Raman analyses. These findings provide valuable visions into the tunability of the electronic properties of HA through controlled doping with Zn, Pr, and Ag. This knowledge is crucial for modifying materials with desirable electronic properties, and thus holds promise for various applications in electronic devices and biocompatible coatings.

Role of Ag and g-C3N4 over CaTiO3 for effective photocatalytic degradation of nitrobenzene

In the present study, g-C3N4/CaTiO3 (GCT) heterostructure with various Ag contents have been synthesized via simple hydrothermal method and characterized using various instrumental techniques. Stability of synthesized samples was measured by thermogravimetric analysis (TGA) and zeta potential measurement. The photocatalytic activity of all the synthesized was evaluated by the degradation of nitrobenzene (NB) in aqueous media. The photocatalytic activity of heterostructure AGCT was observed enhanced under the light irradiation. This would be attributed to the suitable band structure, resulting in the efficient charge separation and transfer of photogenerated charge carriers. The final percentage of degradation was observed 70% with AGCT5 and 64% with AGCT1 which were highest among other catalysts applied after 2 h. The Ag doping in CT catalyst led to antagonist performance, and to better degradation of NB. The multivalency of Ag leads to prevent agglomeration and recombination of electrons and holes and transferring them from Ag to Ca. The reaction rate (2.36 × 10−3 molL−1 min−1 at 20 °C) and percentage degradation (∼70%) were observed to get increased with the increase in the temperature with the apparent activation energy of 40.3 kJ/mol. The enhanced performance at increased temperature was attributed to overcome the energy of activation and high mobility of charge carriers.

Achieving high quality factor and enhanced thermoelectric performance in polycrystalline SnS by Ag doping and Se alloying

The polycrystalline SnS with a similar layered crystal structure and band structure to SnSe exhibits enormous commercial thermoelectric potential due to its lower cost and environmentally friendly characteristics. However, the wider bandgap of SnS leads to low carrier concentration and inferior electrical transport performance. The two-dimensional interlayer hinders carrier transport, leading to interesting and mysterious anisotropic thermoelectric properties. Herein, we reported the optimized electron–phonon transport in anisotropic polycrystalline SnS by Ag doping and Se alloying, realizing a high quality factor B by multiple strategies of optimizing carrier concentration, modifying band structure, and introducing various defects; further potential performance is predicted by the single parabolic band model. Specifically, Ag-doped SnS not only significantly increases the carrier concentration and weighted mobility μw in both directions but also induces multi-scale precipitates proven by the Debye–Callaway model to suppress phonon transport. Moreover, additional Se alloying optimizes the electronic band structure and increases the Seebeck coefficient, further improving μW and boosting the maximum power factor to ∼3.72 μW cm−1 K−2 at 873 K in the out-of-plane direction. Consequently, the synergistic optimization of carrier and phonon transport achieved a high B of 0.7 and a maximum zTmax of ∼0.8 at 873 K in Ag0.02Sn0.98S0.99Se0.01. Additionally, the high B predicted a high zTmax∼1.5 based on optimized carrier transport characteristics, demonstrating the potential great-performance polycrystalline SnS. This work provides a promising avenue for optimizing the zT of polycrystalline SnS by transport engineering.

Influence of Ag Doping on Thermal Conductivity and Magnetic Levitation of Single Grain YBCO Superconductors for High-Temperature Superconducting Maglev

Ag doping in (RE)Ba2Cu3O7−δ [(RE)BCO] bulk high-temperature superconductors has been recognized as an effective way to improve the mechanical and superconducting properties of REBCO bulk superconductors for practical applications such as high-temperature superconducting (HTS) Maglev. Ag2O nanoparticles doped YBCO samples with different doping amounts (x, x varies from 0∼0.5 wt%) were fabricated by Top-Seeded Melt-Growth method (TSMG). The samples’ steady-state thermal conductivity (λ) and the magnetic levitation force (FL) were measured by a testing platform under a similar condition to the HTS Maglev system. The effects of Ag2O doping on the λ and FL of single domain YBCO bulks have been systematically studied. The λ of the c-axis and the ab-plane were calculated through the steady-state heat flow method. We observed that λ increases distinctly when x ≥0.3 wt%. The doping amount of 0.3 wt% has been evidenced to be the optimal value, of which the λ of the c-axis and ab-plane are approximately 52% and 48% higher than the undoped one respectively. According to the results of the FL measurement, we found FL will increase while the relaxation rate of the FL will decrease by adding trace amounts of Ag2O nanoparticles in comparison to the undoped sample. This observation suggests that Ag-doping is an effective way to enhance thermal conductivity as well as the superconducting properties of YBCO superconductors for practical applications.

Improved Resistive Switching Behaviors of Al/Ag-Doped Fe2O3 Film/ITO Devices Fabricated with a Radio-Frequency Co-Sputtering System

We fabricated Fe2O3−x and Ag-doped Fe2O3−x devices with resistive switching behavior by using a radiofrequency cosputtering system. Our results indicated that doping Ag into Fe2O3−x can effectively improve device performance, increasing the data retention test time to beyond 104 s and resulting in switching cycles of approximately ∼3 × 102 times; resistance on/off ratios of approximately ∼103; and mean setting and reset voltages of 0.94 V and −1.35 V, respectively. The improvement in performance had several possible reasons. In our case, conductive filament formation was mainly induced by oxygen vacancies and Ag atoms. X-ray photoelectron spectroscopy showed that oxygen vacancies increased significantly with Ag doping. This phenomenon can improve device performance. Ag atoms served as trap centers, allowing for the easy trapping and release of charges. This effect facilitated the formation of conductive filaments. Ag-doped Fe2O3−x has significant potential for application in resistive switching random access memory devices.

Luminescent properties of low-dimensional ZnO:Ag powders obtained by chemical deposition from aqueous solution

Photoluminescence (PL) spectra of ZnO:Ag highly dispersed powders obtained by chemical deposition from aqueous solution are investigated in the wavelength range between 360 and 750 nm at room temperature under excitation between 250 and 350 nm. Before starting the synthesis, the Ag dopant was introduced into the initial solution in the form of AgNO3 silver nitrate in the amount of 12, 102, and 252 mg. The PL spectra consist of an ultraviolet emission (380 nm) attributed to AgZn acceptor-bound exciton, a short-wavelength violet emission (400 – 450 nm) and a wide long-wavelength yellow-orange emission (560 – 600 nm). With decreasing excitation energy, the violet emission decreases in intensity, while the yellow-orange emission increases. This is caused by the phenomenon of self-absorption of the short-wavelength emission and energy transmission to the centers of the long-wavelength emission. A rapid decrease in intensity of all the PL bands is found for the sample with maximum Ag concentration. This fact is due to the appearance of the second phase in the form of silver oxide and, consequently, a decrease in the concentration of AgZn point defects responsible for the bands.

The Effect of Silver and Samarium on the Properties of Bioglass Coatings Produced by Pulsed Laser Deposition and Spin Coating.

The current study reports the use of silver (Ag) and samarium (Sm) as dopants to improve the properties of standard bioglass in terms of biological performance. This experiment considers thin films of doped bioglass obtained by pulsed laser deposition (PLD) and spin coating (SC). For both methods, some parameters were gradually varied, as the main objective was to produce a bioglass that could be used in biomedical fields. In order to study the morphology, the phase composition and other properties, the samples obtained were subjected to multiple analyses, such as thermal analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FT-IR), Raman spectroscopy, and x-ray diffraction (XRD). Furthermore, the in vitro bioactivity of the samples, as assessed through simulated body fluid (SBF) immersion, as well as immunocytochemistry and evaluation of actin filaments, assessed through fluorescence microscopy, are reported. The results confirmed the formation of the designed vitreous target employed as the source of material in the PLD experiments only at sintering temperatures below 800 °C; this vitreous nature was preserved in the grown film as well. The presence of Ag and Ce dopants in the parent glassy matrix was validated for all stages, from powder, to target, to PLD/SC-derived coatings. Additionally, it was demonstrated that the surface topography of the layers can be adjusted by using substrates with different roughness or by modulating the processing parameters, such as substrate temperature and working pressure in PLD, rotation speed, and number of layers in SC. The developed material was found to be highly bioactive after 28 days of immersion in SBF, but it was also found to be a potential candidate for inhibiting the growth of Gram-negative bacteria and a suitable support for cell growth and proliferation.

Dual improvement in sensitivity and selectivity of SnO2 nanospheres for formaldehyde sensing based on molecular imprinting and Ag doping

In order to develop a gas sensitive material with both high sensitivity and good selectivity, Ag–SnO2 MIPs were designed and synthesized by adopting molecular imprinting technique. Specifically, SnO2 nanospheres synthesized through hydrothermal method were used as substrate. Then, Ag–SnO2 was assembled by decorating nano-sized Ag on the surface of SnO2 nanospheres. Molecular imprinting modification with formaldehyde as template molecules was in next conducted to get Ag–SnO2 MIPs. The morphology, valence and crystal structure of the samples were characterized using SEM, XRD, TEM and XPS. The characterization results showed that uniform SnO2 nanospheres were successfully synthesized with metallic Ag distributed on the surface, and the molecular imprinting process did not change the morphology of the material. According to gas sensing measurement results, it was found that the sensor based on Ag–SnO2 MIPs exhibited superior formaldehyde sensing performance. The molecular imprinting modification effectively improved the sensor's selectivity towards formaldehyde gas. Owning to the catalytic property of Ag, the sensing response of sensor was greatly enhanced. Additionally, Ag–SnO2 MIPs also exhibits high reproducibility and long-term stability.

Mixed potential NH3 sensor based on Ag-Doped La2NiO4+δ sensing electrode

Perovskite-type oxides have attracted extensive focus as sensing electrodes (SE) for NH3 sensors due to their excellent gas-sensing and tunability. The mixed-potential sensor was developed using yttrium stabilized zirconia (YSZ) as the solid electrolyte and non-stoichiometric perovskite oxides La2AgxNiO4+δ (x = 0, 0.025, 0.05, 0.1) as the SE. Due to the Ag doping in the SE, the electrochemical activity was enhanced, and the adsorption capacity of NH3 was further improved. Compared with the La2NiO4+δ-SE-based sensor, the Ag doping in SE significantly improved the response value and sensitivity of the sensor, and the sensor based on La2Ag0.05NiO4+δ-SE had the best capabilities. The response to 200 ppm NH3 was 61.2 mV, and the sensitivity was 8.12 mV/decade (5–25 ppm) and 73.77 mV/decade (50–200 ppm) at 500 ℃. The sensor had a strong anti-interference ability to H2, NO2, NO, CO2, CH4, and the O2 concentrations had little effect on the sensing performance.