Increase In Doping Concentration Research Articles

Unveiling the effect of strain engineering on the electrochemical properties of hydrothermally grown nanostructured indium doped ZnSeO3 for photoanode applications

The crucial role of In as a dopant on the structural, optical, and thermogravimetric characteristics of the zinc selenite (ZnSeO3) nanopowders has been investigated in detail using X-Ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Energy Dispersive Spectroscopy (EDS), Raman spectroscopy, diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, and Thermogravimetric Analysis (TGA). The structural analysis indicates that all patterns are assigned to the ZnSeO3 orthorhombic structure. Also, XRD analysis shows that In3+ ions may have replaced Zn2+ ions, which causes lattice expansion. Both the Debye–Scherrer method, and the Williamson–Hall method have also been applied to study the influence of strain on the calculation of the crystallite size. The crystallite size was observed to increase with an increase in dopant concentration. The FE-SEM corroborated that the prepared samples are orthorhombic, with the EDS and mapping confirming the presence of In as a dopant. Raman spectroscopy results corroborated the XRD results indicating an expansion in the crystal structure of ZnSeO3 with the introduction of dopants. Based on DRS data, the introduction of In decreases the energy band gap of the synthesized ZnSeO3 nanopowder samples from 3.305 to 3.276. PL spectra confirm the presence of indium with the green emission band attributed to dopants dominating the emission. The TGA investigation shows an improvement in the mass loss with the introduction of dopants. EIS results indicated an improvement in the conductivity as the charge transfer resistance decreased from 525.04 to 21.95 kΩ for the undoped ZnSeO3 and 0.75% In–ZnSeO3 thin films showing improvement in charge mobility.

Highly conductive and stable ErxCe0.05Bi0.95-xO1.5+δ solid electrolytes for low-temperature solid-oxide fuel cells

Low-temperature solid oxide fuel cells (LT-SOFCs) are key to meeting China's dual-carbon goal, but existing solid electrolytes suffer from low conductivity. Here, a highly conductive Er/Ce co-doped bismuth oxide (ErxCe5SB, x = mol%) electrolyte is reported. Synthesis is achieved by reverse coprecipitation, and ErxCe5SB has a cubic fluorite structure with a uniform particle size of 100–200 nm, although Er5Ce5SB and Er10CeSB contain a minor rhombohedral phase. Dense pellets (relative density: 93 %) are formed after sintering at 800 °C for 6 h, and the lattice constants decrease with the increase in erbium dopant concentration. Er20Ce5SB had an impressive ionic conductivity of 0.016 S cm-1 at 450 °C. Notably, after being annealed at 600 °C for 4032 h, Er20Ce5SB showcased a commendable stability in conductivity, measuring approximately 0.09 S cm−1, with only a minor drop in its conductivity value. Even after such extended annealing, Er20Ce5SB retained its pure cubic phase structure, devoid of any impurities. Oxygen-ion ordering yields a superstructure, as observed by HR-TEM. Because of its high conductivity and long-term stability, Er20Ce5SB is a promising LT-SOFC electrolyte material.

Structural, magnetic and optical properties of nickel doped iron oxide nanoparticles based on Logas natural sand for environmental application

The iron oxide nanoparticles have been prepared by mechanical milling method using Logas natural sand as a raw material. The products of ball milling were doped with Ni nanoparticles at different doping concentrations (0, 1, 2, 3, and 4 wt.%). The effect of doping concentration on the structural, magnetic, and optical properties was studied. The structural, magnetic, and optical properties of the prepared samples were studied using an X-ray diffractometer (XRD), vibration sample magnetometer (VSM), and UV-Vis spectroscopy, respectively. The X-ray diffraction pattern shows that the ball milling product is hematite (α-Fe2O3) nanoparticles and highly crystalline with a rhombohedral structure. It is very interesting to find that Ni doping nanoparticles cannot change the structure of iron oxide nanoparticles however, the average crystallite size decreases from 39.43 to 32.64 nm with increasing Ni doping concentration from 0 to 4 wt. %, respectively. The crystallite size based on the dominant peak (104) varies as Ni doping concentration increases. The magnetic properties of the samples show the ferromagnetic nature of the prepared nanoparticles. The saturation, remanence magnetization, and coercivity increase with increasing Ni concentration. The optical band gaps calculated through UV-Vis absorption measurements confirm that the decrease in crystallite size is accompanied by a decrease in the band gap value from 2.03 to 1.92 eV as the doping concentration increases from 0 to 4 wt. %.This study demonstrates the simple way of preparing Ni-doped iron oxide nanoparticles for environmental application.

Study on the electrochemical effect of ZnO addition on flash sintering of 3 mol% yttria stabilized zirconia

Flash Sintering has shown tremendous promise in reducing the sintering time and temperature. However, significant heterogeneity in densification and microstructure was observed in the flash-sintered sample due to hotspot formation and electrochemical effects (electrochemical blackening). In this work, we have varied the extent of electrochemical reaction by (0.75-3 mol%) ZnO addition during flash sintering of 3 mol% yttria-stabilized Zirconia (3YSZ). A substantial increase in grain size was observed throughout with an increase in dopant concentration. With the addition of 0.75 mol% ZnO dopant in 3YSZ, a significant improvement in densification and a significant reduction in the presence of cracks were observed. The extent of electrochemical blackening was seen to be increasing with the increase in dopant concentration. The blackened phase was found to be distorted tetragonal Zirconia by Raman analysis. The ZnO doped 3YSZ showed ionic to electronic transition in conduction during flash sintering likely due to electrochemical effects.

Synthesis of yttrium doped zinc oxide nanorods for display, forensic and supercapacitor applications

Yttrium (1–7 mol %) doped Zinc Oxide (ZnO) nanoparticles (NPs) are synthesized by hydrothermal method followed by calcination. The synthesized NPs are characterized by different techniques. The Bragg reflections confirm the formation of a hexagonal wurtzite crystal structure. The crystallite size is estimated by both Scherrer’s and Williamson’s-Hall plot methods. The surface morphology is decorated with nanorods of different sizes with sharp edges. As the dopant concentration increases changes in their alignment were also observed. The direct energy band gap determined from Wood and Tauc’s relation was found to be increased from 3.183 to 3.197 eV with an increase in the dopant concentration. The photoluminescence emission spectra excited under 344 nm shows less intensity peaks in the blue and green region whereas the high-intensity peaks are observed in the red region. The concentration quenching is observed at 5 mol % yttrium concentration. This concentration quenching is caused due to dipole–dipole interaction. Further, the Commission Internationale de I’Eclairage (CIE) coordinates fall in a purplish-red region. The average Color Correlated Temperature (CCT) value of 3595 K clearly indicates that the present synthesized NPs might find an application in warm display technology as a nano phosphor material. For oxidation and redox peaks, cyclic voltammetry analysis is also carried out. Ion transport kinetics were disclosed by Electrochemical impedance spectroscopy (EIS), and super capacitance values were acquired using Galvanostatic Charge Discharge (GCD) analysis. For ZnO:Y (1–7 mol %) NPs, specific capacitance values were discovered to be in the range of 33 to 74 F/g with a change in dopant concentration. Therefore, the currently synthesized material may find use in both energy storage materials and the field of display technology and latent fingerprints (LFPs).

Multiphysics Modeling and Analysis of Sc-Doped AlN Thin Film Based Piezoelectric Micromachined Ultrasonic Transducer by Finite Element Method.

This paper presents a Piezoelectric micromechanical ultrasonic transducer (PMUT) based on a Pt/ScAlN/Mo/SiO2/Si/SiO2/Si multilayer structure with a circular suspension film of scandium doped aluminum nitride (ScAlN). Multiphysics modeling using the finite element method and analysis of the effect of different Sc doping concentrations on the resonant frequency, the effective electromechanical coupling coefficient (keff2) and the station sensitivity of the PMUT cell are performed. The calculation results show that the resonant frequency of the ScAlN-based PMUT can be above 20 MHz and its keff2 monotonically rise with the increasing doping concentrations in ScAlN. In comparison to the pure AlN thin film-based PMUT, the static receiving sensitivity of the PMUT based on ScAlN thin film with 35% Sc doping concentration is up to 1.61 mV/kPa. Meanwhile, the static transmitting sensitivity of the PMUT is improved by 152.95 pm/V. Furthermore, the relative pulse-echo sensitivity level of the 2 × 2 PMUT array based on the Sc doping concentration of 35% AlN film is improved by 16 dB compared with that of the cell with the same Sc concentration. The investigation results demonstrate that the performance of PMUT on the proposed structure can be tunable and enhanced by a reasonable choice of the Sc doping concentration in ScAlN films and structure optimization, which provides important guidelines for the design of PMUT for practical applications.

Enhancing antimicrobial and photocatalyst properties of Mg-doped ZnO nanotubes via novel laser-assisted chemical bath synthesis

Laser-Assisted Chemical Bath Synthesis (LACBS) was used to fabricate pure and magnesium-doped zinc oxide nanoparticles. Analysis of these nanoparticles' structural, morphological, optical, and antimicrobial characteristics was conducted. This analysis spanned across varying concentrations of magnesium-doped zinc oxide from 1 % to 3 %. XRD confirmed the nanoparticles' crystalline nature, revealing the hexagonal wurtzite phase. SEM analysis showcased their nanometric domain existence and hexagonal crystalline morphology, transforming from nanorods to nanotubes. Optical analysis showed band gap energy decrease from 3.27 to 2.85 eV correlating with the magnesium doping concentration increase. Optical absorption displayed a distinctive redshift for the nanoparticles as magnesium concentration increased from 1 % to 3 %. Photocatalytic assessments highlighted the superior degradation ability of 3 % Mg-doped nanoparticles, showing a 98.04 % degradation rate against methylene orange dye under blue light exposure. Antimicrobial activity tests against various pathogens showed that Mg ions' incorporation significantly enhanced antimicrobial performance, demonstrating the effectiveness of the LACBS method.

(K0.5Bi0.5)(Mg1/3Nb2/3)O3‐modified Sr0.7Bi0.2TiO3 lead‐free ceramics for energy storage applications

AbstractIn the present study, Sr0.7Bi0.2TiO3 is mixed with [(K0.5Bi0.5)(Mg1/3Nb2/3)O3] to form a solid solution of [(1 − x)SBT–x(KB)(MNb), x = 0.02, 0.04, 0.06, 0.1]. From the XRD results, it is indicated that KB is the main substituent for SBT ceramic at the A‐site. The breakdown strength (BDS) of ceramic gradually increases with an increase in doping content and achieves a high value of 280 kV/cm for x = 0.06. In addition, the 0.94SBT–0.06(KB)(MNb) ceramic shows excellent temperature stability (−55 to 140°C), a high recoverable energy density (Wd)—2.6 J/cm3, and an efficiency (η)—88% at 280 kV/cm. Therefore, 0.94SBT–0.06(KB)(MNb) ceramic is one of the possible materials for energy storage capacitor applications.

Nonlinear optical characteristics of chemical bath-deposited pure and Cu-doped SnO2 thin films: A comparative evaluation

A chemical bath deposition method is used to grow SnO2 thin films doped with copper (0, 1, 2, and 3 wt) on glass substrates that exhibit linear and nonlinear optical properties. XRD analysis of the films verified their polycrystalline phases oriented strongly of the c-axis along the preferred (110) direction depending on the doping concentration and substrate temperature. SEM images of pure SnO2 film showed the formation of granular cubic structures. Conversely, the Cu-doped films displayed the existence of spherical granules with porosity. The transmittance spectra of the films for UV–visible light indicated large values for pure films, and that the transmittance decreased with greater doping levels. As a result of copper ions in the nanostructures, it was found that the transmittance decreased as doping levels increased. Pure SnO2 has an optical band gap of 3.63 eV; it decreases with increasing Cu doping concentrations. Wemple-Di Domenico (WDD) model for single oscillator energy was used to estimate each oscillator's optical refractive index, while the static refractive index and dispersion energy were also determined. In addition, the film's WDD parameters and nonlinear refractive index were in the range of 320–1200 nm, and the wavelength was determined. During the doping concentration increase, the nonlinear refractive index of the films increased primarily because the linear refractive index of the films at 520 nm increased. This nonlinearity of the film may arise because of the thermal effect, saturated atomic absorption, and electrostriction. For pure SnO2, third-order nonlinear susceptibility (2.77 × 10-12m2/V2) is caused by thermal effects, and for doped samples, it is caused by photorefractive effects.

Dynamic photoluminescent and photochromic properties of CaAl12O19:Eu, Tb: A novel phosphor for advanced dual-modal multicolor anticounterfeiting

The integration of dynamic photoluminescence and photochromism to achieve dual-modal characteristics can substantially elevate the security of anticounterfeiting measures. In this study, a novel bifunctional phosphor, namely CaAl12O19:Eu, Tb possessing dynamic photoluminescence and photochromism, is developed by the sol-gel combustion method. As the duration of exposure to 254 nm ultraviolet radiation increases, the CaAl12O19:Eu, Tb phosphors exhibit exceptional dynamic luminescent characteristics and pronounced color changes. Furthermore, this exposure results in a photochromic phenomenon on the surface of the samples, causing a shift from white to light brown. With an increase in Tb doping concentration, distinct and diverse chromatic variations easily discernible are observed by the naked eye. In addition, the mechanisms underlying the dynamic photoluminescent and photochromic characteristics are analyzed herein. Furthermore, the application of the bifunctional phosphor CaAl12O19:Eu, Tb for advanced dual-modal multicolor anticounterfeiting is explored, offering enhanced security against duplication attempts.

Efficient bright green phosphor for white light-emitting diode using in backlight application

The (Ba,Ca)ScO2F:Bi3+,K+ phosphor with narrow emission band and green emission color peaking at 510 nm is demonstrated in the study. This phosphor is prepared using a solid-state reaction at high temperatures. Based on characterizing data, the increasing concentration of Ca2+ induces the shrinkage of the unit cell and the narrower spacing, leading to the increase in the photoluminescence of the phosphor. This also cause a red shift in the emitting range from 504 nm to 510 nm. The phosphor shows good absorption peaking at 415 nm, matching the excitation wavelength of the used nearultraviolet (UV) light emitting diode (LED) chip. When being applied in a white light‐emitting diodes (WLED) with 4,000 K, the phosphor could increase the luminous flux as its doping concentration increase. Besides, the WLED doping (Ba, Ca) ScO2F: Bi3+, K+ shows emission regions in blue, green, and red wavelength bands. The data from the study indicates that the phosphor is potential for developing the white-LED for backlight purposes.

Low temperature magnetic and structural properties of Sr-doped La2CoMnO6 (La2-xSrxCoMnO6: 0 ≤ x ≤ 0.08) double perovskite nanoparticles

A study on crystal structure and physical properties has been performed on nanoparticles of lead-free double perovskites, La2CoMnO6 (LCMO) and Sr-doped La2-xSrxCoMnO6 (LSMO:0 ≤ x ≤ 0.08) prepared by the sol–gel synthesis method. In preparation for the LSMO nanoparticle, the La site of the LCMO double perovskite was replaced with an increasing concentration of Sr atom. Structural investigation done by employing the X-ray Diffraction technique indicates that the crystallite size decreases as the doping concentration increases. The Rietveld refinement on the XRD pattern shows the formation of the rhombohedral phase of LCMO (S.G. no. 161). Strain in the prepared samples estimated from Williamson Hall (W-H) analysis shows that the strain decreases as crystallite size decreases. The presence of compressive strain is also evident from the blue shift obtained in the Raman spectrum of the nanoparticles. The UV–Vis spectra reveal the maximum absorption in the near UV region of the electromagnetic spectrum. The Bandgap analysis from Tauc’s plot shows an increase in band gap with Sr doping in the LCMO host lattice (from 1.81 eV to 1.92 eV). This is attributed to the decrease in crystallite size and octahedral tilting with Sr doping. Resistivity versus temperature plots reveal the semiconducting nature of the compound. A linear nature graph between lnρ and T-14 indicates that the electric transport mechanism is governed by the variable range Hopping (VRH) model. The M−H curves show that the maximum magnetization decreases as a result of Sr doping due to the anti-site disorder introduced. dM/dT vs T curve shows two magnetic transitions at ∼ 215 K and at ∼ 173 K which are due to Co2+–O2--Mn4+ and Co3+–O2--Mn4+ ferromagnetic superexchange interactions, respectively.

Monocrystalline silicon materials with the group IVA elements doped: A first-principles analysis

In this paper, the changes of lattice constant, stability and electronic structural properties of Si64−xMx (M=C, Ge, Sn, Pb; x=0, 1, 2, 3, 4) doped system under various doping types and concentrations were studied by using first principles calculation to determine the influence of doped IVA family elements on the properties of monocrystalline silicon materials. The results have shown that, the Ge, Sn and Pb doped systems will produce an expansion effect, and the lattice constant of the C doped system will decrease with the increasing of the number of doped atoms, and will have the greatest impact on the lattice constant of the system. The increase in defect formation energy is Pb¿C¿Sn¿Ge, the Ge doped system is the easiest to synthesize; and as the doping concentration increases, the defect formation energy of each doping system also increases, indicating that high concentration doping systems are more difficult to synthesize. There are no virtual frequencies in the phonon spectra of all doped systems, and the systems are thermally stable. In addition, doping will gradually reduce the bandgap width as the doping concentration increases. The band gap characteristics will also change: when doped with C, the system will become Metalloid; when doped with Ge, the system remains unchanged; when doped with Sn and Pb, the system will become a direct band gap semiconductor. From the perspective of band gap and charge differential density, the effect of different doping elements on enhancing electronic transitions is C¿Pb¿Sn¿Ge. This means that C doping system has the best improvement in conductivity.

Antimony doped tin oxide MOS sensors for hydrogen detection at low concentrations

In this study, Antimony (Sb) doped tin oxide (SnO2) thin films (ATO) were synthesized using the RF (radio frequency) sputtering technique with varying antimony concentrations (0, 3, 5, 7 wt%) and substrate temperatures of room temperature, 150 ℃, and 300 ℃. It was discovered that these thin films were tetragonal crystal structures with good crystallinity and grew preferentially along the (101) planes at the substrate temperature of 300 ℃. It was found that the 5 wt% doped film prepared at 300 ℃ substrate temperature exhibited superior gas-sensing properties under all tested conditions, and the 7 wt% doped sample showed properties that deviated from the trend observed up to 5 wt%. It was observed that the morphology of the film has a spongy spherical granular structure with a mesoporous surface. The presence of Sn, Sb5+/Sb3+, and oxygen was confirmed by XPS spectra analysis in the thin films. The n-type electrical conductivity was attained by combining an oxygen vacancy and antimony ions in the tin oxide lattice interstitial. Consequently, the inclusion of antimony increased conductivity up to 5 wt% was noticed. Doping makes remarkable changes in surface roughness (14–163.48 nm), which is attributed to the surface wettability. The film turns nearly hydrophilic when the doping concentration increases (59°). According to studies into a potential gas-sensing mechanism, the addition of Sb dopants, mesoporous structures, and high specific surface area was thought to be the reason for the improved gas-sensing response. Without a doubt, the current work may offer the best method to enhance H2 gas response in particularly environmentally sensitive applications.

Achieving high energy storage performance and efficiency in lead-free SrTiO3 ceramics via neodymium and lithium co-doping technique

ABSTRACT There is an immediate demand for eco-friendly, high-performance, and highly stable energy storage materials for pulse power systems. Ceramics based on SrTiO3 have a high breakdown strength (BDS) and dielectric constant. In this work, we fabricated a polycrystalline of Sr(1-x)(Nd, Li)xTiO3 ceramics via microwave-assisted heating of the starting materials. X-ray diffraction analysis reveals a pure perovskite phase without any secondary phase. Scanning electron microscopy images exhibit dense grain morphology with a decrease in grain size as the dopant concentration increases. The frequency dependences of the dielectric properties were studied in the frequency range of 100 Hz-1 MHz at room temperature. The polarization-electric field hysteresis loops were examined to ascertain the effect of co-doping on the energy-storage capability of SrTiO3 ceramics. After increasing the co-dopants from 0 to 8%, the energy density increased nine times (from 0.11 J/cm3 to 0.952 J/cm3), and the energy storage efficiency increased from 80.71% to 95.98%, respectively. In addition, the samples demonstrate excellent thermal stability, and their energy storage properties are stable up to 80°C. We may infer from this discovery that the bulk Nd3+ and Li+ co-doped SrTiO3 materials are good candidates for high-energy-density capacitor applications.

Modified physical properties of Ni doped ZnO NPs as potential photocatalyst and antibacterial agents

Hazardous organic dyes, present in the effluents of industries, are continuously polluting the environment. Photodegradation of these dyes on catalyst surface under sunlight irradiation is economic, safe and suitable strategy to protect environment. Hence, the synthesis and applications of Zn1-xNixO (x = 0.00, 0.02, 0.04, 0.06) NPs are reported here. Effect of pH and dopant concentration was studied to modify the electrical, magnetic, antibacterial and photocatalytic properties of Ni doped ZnO NPs. The samples were characterized by Scanning electron microscopy (SEM), Powder X-ray diffraction (XRD), UV–Visible spectroscopy (UV–Vis.), Energy-dispersive X-ray spectroscopy (EDS) and Fourier-transform infrared spectroscopy (FTIR) to determine the morphology, crystallite structure, optical properties, elemental composition and functional group detection, respectively. LCR meter and VSM were used to evaluate the dielectric properties and magnetic properties of Ni doped ZnO NPs, respectively. XRD pattern confirmed the presence of hexagonal wurtzite geometry of ZnO NPs. The structural and morphological analysis showed the increase in crystallinity with little effect on shape of doped NPs by increasing the dopant concentration and slight increase of pH. It was observed that the Ni doped ZnO NPs possess good photocatalytic potential by 94% degradation of 20 ppm solution of methyl orange dye (MO) in just 80 min under sunlight. Moreover, the enhancement in antibacterial potential was also observed with increase in dopant concentration and decrease in crystallite size of doped ZnO NPs. Smaller size NPs were found more effective against gram negative bacterial strains.

Structural, Morphological, Optical Properties and Impedance Analysis of Solution-Processable Ni-Doped CuO Thin Films on ITO/Glass Substrates

Cupric-oxide-based thin films with various amounts of 0, 1, 2, 3, and 4 wt.% Ni doping were, in turn, deposited on ITO/glass substrates via a solution process. The 0.25 M concentrated solutions of copper (II) acetate monohydrate and nickel acetate tetrahydrate were used as starting materials mixed in ethanol solvent, in order to form the precursors. We obtained that the crystalline structure was not affected by the increase in Ni doping concentration as evidenced by X-ray diffraction patterns. The surface morphology observed by scanning electron microscope pointed out the presence of linked-structure nanoparticles. The influence of Ni doping on the optical bandgap width was evaluated by using ultraviolet-visible spectrometry. We found that the optical bandgap should be direct, and it decreased from 2.69 to 2.38 eV for the range doped. Interestingly, we determined the relaxation time of the Ni-doped CuO/ITO/glass structure from measuring the electrochemical impedance spectroscopy, and it was 0.36 s for the undoped film, then gradually decreased to be 0.31, 0.11, 0.1, and 0.04 s with increasing the Ni doping concentration. This achievement result will serve as a foundation for the future photonic researches.

Robust ferromagnetism and magneto-dielectric anomalies in (Al, Cr) co-doped iron oxide thin films-microwave mediated sol–gel approach

Research on thin films of iron oxide has gained interest in recent years because of its application in advanced spintronic and electronic devices. Technologically important iron oxide phases can be achieved by adopting novel methodologies and/or selecting suitable dopants. A cost-effective microwave assisted sol–gel approach is adopted in this work to prepare thin films of iron oxide. Undoped and doped sols (2–10 wt% of dopant concentration) are irradiated with MW power of 720 W. Maghemite phase (γ-Fe2O3) is observed to be stable up to a co-dopant concentration of 6 wt%. Further increase in dopant content leads to a phase transition to mixed (γ-Fe2O3+Al2O3) crystal phases. Values of dielectric constant (DC) and loss tangent exhibit normal dispersion response with high DC value (log f 5.5 = ∼92) observed for undoped sample. Cole–Cole plots indicate the effective grain boundary contribution for low dopant concentrations, whereas contributions from grains is observed at higher dopant concentrations. M−H curves show ferromagnetic response with high value of saturation magnetization (Ms) of ∼450 emu/cm3 witnessed at 6 wt%. (Al, Cr) co-doping results in tuning of magnetic response/parameters. MD coupling of (Al, Cr) co-doped thin films of iron oxide makes this material suitable for advanced spintronic and energy storage devices.

Improve physical properties of zirconium doped strontium sulphide for optoelectronic purpose

The electrochemical deposition was used to synthesize zirconium-doped strontium sulphide materials at varying dopant concentrations of 0.01 to 0.03 mol. The surface micrograph of the zirconium doped films is well structured on the surface of the FTO used for the synthesis without any crack or lattice strain. The spectrum is polycrystalline with a cubic structure and a prominent peak at (111) orientation for SrS film. At the introduction of the zirconium dopant 0.01 mol, the peak intensity increases with a prominent peak at (211) which indicate acceptance of zirconium dopant in the precursor and as the dopant concentration rises the peak intensity decreases which depicts that a higher concentration of zirconium reduces the peak intensity of the films. The Williamson-Hall plot's slope increases as the dopant concentration increases. The materials exhibit a thickness increase of 121.32 to 126.13 nm and a decrease in film resistivity from 1.12 × 109 to 1.32 × 109 O.m, which further led to an increase in conductivity from 7.57 × 108 to 8.26 × 108 S/m. The bandgap energy of SrS is 1.50 eV while SrS-doped zirconium is 1.35 eV–2.52 eV.

Benchmarking the yttrium content in the low temperature/low humidity electrical properties of yttrium-doped barium cerate

Yttrium-doped barium cerate (BCY) is one of the best proton-conducting ceramics to be used in fuel cells/electrolyzers at intermediate temperatures, due to its high hydration enthalpy and high conductivity. Nonetheless, it has commonly been discarded for these applications due to its instability in the presence of carbonaceous and humidified atmospheres. A recent work has addressed this issue, by suggesting the use of this material in very low water vapor partial pressures (pH2O ∼ 10−4 atm) [Electrochimica Acta 334 (2020) 135625] and at low temperatures (T ≤ 400 °C). Under these conditions, BCY can still offer pure protonic conductivity while also offering suitable stability. In the current work, we provide a comprehensive analysis of the effects of the acceptor dopant concentration (Y2O3) in the structural, microstructural, and electrical properties in a wide compositional series of BaCe1-xYxO3-δ (x = 0.05, 0.10, 0.20 and 0.30) at low levels of humidity in the low temperature range (100–400 °C). The results show that BaCe0.9Y0.1O3-δ (BCY10) offers the highest bulk conductivity in these conditions, while further increase in dopant concentration leads to impairment due to “proton trapping” effects. In contrast, the specific grain boundary conductivity increases with increasing dopant concentration due to a reduction of Schottky barrier height at the space-charge layer. We demonstrate that, by operating at very low temperatures (e.g., below 400 °C), the peak performing, BCY10 material can still operate at very low levels of water vapor partial pressure (pH2O ∼ 10−4 atm), where its stability can be maintained. This work paves the way for the optimization of this material, with a focus on utilizing low humidity levels and low temperatures, where it can offer a competitive advantage over that of the majority of other proton-conducting perovskites for potential applications operating under these conditions.