Effect Of Al-doping Research Articles

Suppressing the Memory Effect in Al Doped 3C-SiC Grown Using Chlorinated Chemistry

The memory effect of Al doping in 3C-SiC prevents sharp interfaces between layers of different doping levels and can lead to unintentional doping of subsequent epilayers and even growth runs. Introducing HCl into the growth phase of 3C-SiC reduces the Al incorporation but has a significant impact on Al dopant decay rates and background levels within the chamber, resulting in far sharper doping profiles. The impact of relatively high flow rates of HCl is low within a chlorine-based growth system giving fine control over its influence on the growth process and memory effect.

Effect of Al and Si content on properties of Ti(1-x-y)AlxSiyN coating materials: First-principles calculation

This paper investigates the effect of Al and Si atomic doping on the Ti(1-x-y)AlxSiyN alloy using density functional theory (DFT). The results indicate that the phase structure stability of the alloy decreases with increasing Al and Si doping content. Particularly, excessive doping leads to the transformation of crystal structure from rocksalt to wurtzite structure with lower mechanical properties. The bulk modulus of the alloy decreases with the increase of doping content. Specifically, Al atom doping initially reduces and then increases the shear modulus and Young's modulus of Ti1-xAlxN, while Si atom doping causes the shear modulus and Young's modulus of Ti0.375-yAl0.625SiyN to increase first and then decrease. In terms of hardness, the hardness of Ti1-xAlxN increases with the increase of Al doping, but the toughness decreases. Si atom doping further enhances the alloy's hardness, reaching a maximum of 29.8 GPa, consistent with the trends observed in experimental results. Electronic structure analysis reveals that Al and Si doping induces orbital hybridization, enhancing the bonding ability and chemical bond strength between atoms. The results confirm that the ionic bonds, metal bonds and covalent bonds in multi-component nitride jointly determine the mechanical properties of the alloy.

Enhancing radiation-hardness of Si-based diodes: An investigation of Al-doping effects in Si using I–V measurements

The impact of radiation on Si-based detectors garnered interest due to the observed degradation in their stability in high-radiation environments. In this study, we examined the effects of 3 MeV proton irradiation on both undoped and Al-doped n-Si diodes using I–V technique. The results revealed a decline in current trends for both types of diodes post-irradiation. This decrease was attributed to defects created by proton irradiation, which acted as recombination or trapping centres. However, the Al-doped n-Si diodes experienced a lesser decline in measured current, hinting at the radiation suppression effect of Al doping in Si. Additionally, Al-doped n-Si diodes displayed minimal changes in their diode parameters after irradiation, and their conduction mechanism remained unchanged. These results suggested that Al-doped n-Si diodes had superior stability compared to their undoped counterparts, implying that the presence of Al enhanced the diodes' resistance to radiation. The radiation suppression effect of Al seemed to stem from its ability to produce defects that improve Si's radiation-hardness, thereby mitigating the introduction of additional instability-causing defects during proton irradiation. Thus, incorporating Al was recommended for research aiming to improve the radiation resistance of Si.

Bulk Al-doping effect on structure and electrochemical performance of NCM811 cathode materials

Bulk Al-doping effect on structure and electrochemical performance of NCM811 cathode materials

2D-on-2D Al-Doped NiCo LDH Nanosheet Arrays for Fabricating High-Energy-Density, Wide Voltage Window, and Ultralong-Lifespan Supercapacitors.

Battery-type electrode materials with high capacity, wide potential windows, and good cyclic stability are crucial to breaking through energy storage limitations and achieving high energy density. Herein, a novel 2D-on-2D Al-doped NiCo layered double hydroxide (NiCoAlx LDH) nanosheet arrays with high-mass-loading are grown on a carbon cloth (CC) substrate via a two-step hydro/solvothermal deposition strategy, and the effect of Al doping is employed to modify the deposition behavior, hierarchical morphology, phase stability, and multi-metallic synergistic effect. The optimized NiCoAl0.1 LDH electrode exhibits capacities of 5.43, 6.52, and 7.25 C cm-2 (9.87, 10.88, and 11.15 F cm-2) under 0-0.55, 0-0.60, and 0-0.65V potential windows, respectively, illustrating clearly the importance of the wide potential window. The differentiated deposition strategy reduces the leaching level of Al3+ cations in alkaline solutions, ensuring excellent cyclic performance (108% capacity retention after 40000 cycles). The as-assembled NiCoAl0.1 LDH//activated carbon cloth (ACC) hybrid supercapacitor delivers 3.11 C cm-2 at 0-2.0V, a large energy density of 0.84 mWh cm-2 at a power density of 10.00mW cm-2, and excellent cyclic stability with ≈135% capacity retention after 150000 cycles.

A Single-step Synthesis of Aluminum-Doped WS2 for Oxygen Evolution Reaction with Loading Influence on Catalytic Performance

Recently, tungsten disulfide (WS2) has received considerable attention in aspects of electrocatalytic oxygen evolution reactions (OER). However, due to the restricted number of active sites, WS2 nanoflower has a high overpotential in OER. Thus, we provide herein a doping approach for doping WS2 nanoflower with non-noble aluminum (Al) metal to increase active sites in an effort to enhance the OER activity of WS2. The positive electrocatalytic effect of Al-doping on WS2 material results in a lower OER operating overpotential. In comparison to undoped WS2, the skeleton-like structure (0.04 %) Al-doped WS2 nanoflowers significantly enhanced OER catalytic activity with an overpotential of 650 mV at the current density of 6 mA cm−2. Furthermore, the impact of different mass loadings of (0.04 %) Al-WS2 on the OER performance has been examined using electrochemical analysis. The success of using aluminum dopants to improve OER performance would have a significant impact on the development and production of non-noble metal sulfide-based electrocatalysts for OER.

Effect of Al-Doping on Structural and Adsorption Properties of NiFe2O4 via Modified Sol–Gel Approach for CO2 Adsorption

Effect of Al-Doping on Structural and Adsorption Properties of NiFe2O4 via Modified Sol–Gel Approach for CO2 Adsorption

Slug-flow synthesis of NCMA: Effect of substitution of cobalt with aluminum on the electrochemical performance of Ni-rich cathode for lithium-ion battery

Nickle-rich Li[Ni1-x-yCoxMny]O2 (x, y ≤ 0.1) (NCM) layered materials are known as promising cathode materials for next-generation lithium-ion batteries and electric vehicles owing to their high-reversible capacity and operating voltage of up to 3.6 vs Li/Li+. However, issues, such as irreversible phase transition, cation mixing, microcrack formation, thermal and structural stability of the material prevent its widespread adoption. Although, cation doping is a well-known technique to enhance the electrochemical performance of the NCM-based cathode material, the performance of the material is very sensitive to the doping amount. In this study, three Al-doped quaternary Ni-rich cathode materials Li[Ni0.85Co(0.1-x)Mn0.05Alx]O2 (where, x = 0–0.04) (NCMA) are synthesized through three-phase slug-flow based continuous manufacturing process followed by high temperature calcination to study the effect of Al-doping on the performance of the cathode material while reducing Co. The slug flow-based production platform has several advantages, like particle size uniformity, high production rate, and homogeneity in elemental distribution. It is found that with an increase in Al content, the specific capacity decreases but the cyclic stability and rate capability increases. Optimum Al-doping not only compensates for the adverse effect of low Co by decreasing the extent of cation mixing, but it also minimizes the electrode polarization and cracking of the particles.

Detection of NO2 at ppm-level using Al-doped CeO2 based gas sensor with high sensitivity and selectivity at room temperature

Nanostructured metal oxides have gained significant attraction in the field of gas sensors because of their size-dependent, superior catalytic capabilities with better gas adsorption and desorption behaviour. However, their high operating temperature limits their scalability in real-time applications. In this work, we fabricated the pristine and Al-doped CeO2 nanoparticles for Room-Temperature (RT) NO2 detection. Compared to other interfering gases, the fabricated sensor shows a strong preference for detecting NO2, indicating a high level of selectivity. Interestingly 5% Al-doped CeO2 exhibited a remarkable 247% response to 25 ppm of NO2, which is three times greater than the pristine. Furthermore, the sensor exhibits improved response and recovery times of 64 s and 52 s, respectively. It also demonstrates excellent repeatability and stability of 91% over the period of 56 days. Thus, the significant improvement in the sensing performance is attributed to the increase in oxygen vacancies, charge imbalance and enhancement in specific surface area due to the effect of Al doping. Furthermore, these findings will provide a new approach to develop real-time gas sensors for room temperature applications.

Synergistic effects of aluminum doping and amino functionalization to enhance adsorption capacity of ultrathin-nanosheet-assembled calcium silicate hydrate architectures for effective removal of Pb2+ and Cu2+ from aqueous solution

This study demonstrates for the first time the potential of the novel combination of aluminum (Al) doping and amino functionalization to drastically enhance the adsorption capacity of nanosheet-assembled hierarchical calcium silicate hydrate (CSH) architectures for heavy metal Pb2+ and Cu2+ ions in aqueous solution. The designed and prepared amino-functionalized Al-doped CSH (CASH-NH2) exhibits excellent adsorption capability to adsorb Pb2+ and Cu2+ ions. The maximum adsorption capacity of Pb2+ and Cu2+ ions is 911 and 509 mg g−1, respectively, which is much higher than that of pure CSH and other relative CSH-based adsorbents. The experimental measurements of cation exchange capacity (CEC) and surface composition discover that the adsorption of Pb2+ and Cu2+ ions on CASH-NH2 is preponderantly achieved by the cation exchange and surface complexation, in which Al doping substantially enhances the exchange capacity between Ca2+ of CSH and Pb2+ or Cu2+, and the functional amino groups chelate Pb2+ or Cu2+ to realize surface complexation of CASH architectures. Thereby the excellent adsorption performance of CASH-NH2 is attributed to the significant enhancement in the CEC between Ca2+ of CASH and Pb2+ or Cu2+, and the amino functionalization-induced surface complexation of the CASH, which are achieved by the synergistic effect of Al doping and amino functionalization. This work opens a new way for simultaneously exploiting metal doping and amino functionalization to boost the adsorption performance of other adsorbents to achieve highly efficient removal of toxic cationic species from polluted water.

The Effect of Al and Sn Doping on the Optical and Electrical Properties of ZnO Nanostructures

The Effect of Al and Sn Doping on the Optical and Electrical Properties of ZnO Nanostructures

Effect of Al-doping on dosimetric properties of CaF2

In this study, the effect of Al-doping on dosimetric properties of CaF2 was investigated. Al-doped CaF2 showed a radiophotoluminescence (RPL) peak at 750 nm after X-ray irradiation. The RPL intensity decreased with the increase of Al concentration and was less than that of undoped CaF2. The minimum detectable dose as the RPL dosimeter of 0.01% Al-doped CaF2 was 42 mGy. Al-doped CaF2 also indicated thermally stimulated luminescence (TSL) glow peaks at 225, 285, 387, and 436 °C. The wavelengths of TSL were 390 and 500 nm. The minimum detectable dose as the TSL dosimeter of 1% Al-doped CaF2 turned out to be 0.43 μGy which is comparable to commercial dosimeters.

Effect of Al-doping on structural and cyclic stability of NiCoFe layered double hydroxides as electrode material in supercapacitors

Supercapacitors are an effective energy storage device can address the issue of storing renewable energy sources. Layered double hydroxides (LDHs) have been identified as a promising electrode material for supercapacitors due to their diverse constituent elements and adjustable structure. However, LDHs tend to experience mechanical deformation during charging and discharging, which results in poor cycle performance. In this study, an Al substitution strategy for Fe was employed to adjust the interlaced structure assembled by one-dimensional nanorods and two-dimensional nanosheets in NiCoFe-LDH, which led to an enhanced stability and electrochemical performance for supercapacitors. Excessive Al doping prompted nanorods to evolve into nanosheets, resulting in loss of the interlaced structure. When the ratio of Fe and Al is 0.75:0.25, the resulted Ni2Co1Fe0.75Al0.25-LDH maintained a much more perfect interlaced structure while exhibiting the best specific capacitance reaching 2367.39 F·g−1 at 1 A·g−1 as well as a 89.79% retention rate at 20 A·g−1 in a three-electrode unit; when paired with activated carbon (AC), it exhibited a specific capacitance of 394.14 F·g−1 at 1 A·g−1 with an energy density up to 140.14 Wh·kg−1 at a high power density level of 811.46 W·kg−1 in Ni2Co1Fe0.75Al0.25-LDH//AC unit. Moreover, after undergoing rigorous testing involving 5000 cycles at 5 A·g−1, Ni2Co1Fe0.75Al0.25-LDH//AC demonstrated a 55.31% retention rate, significantly higher than that observed for Ni2Co1Fe1-LDH//AC (17.58%). The Al doping strengthened the stability of host layer structure and further improved the interlaced structure of LDH, resulted in a significant improvement in specific capacitance, energy density and cycle performance. This improved material will exhibit better application prospects in supercapacitors.

O2 adsorption on Fe3O4 (110) surface and effect of gangue element Al doping: combined study of binding experiment and ab initio molecular dynamics

O2 adsorption on Fe3O4 (110) surface and effect of gangue element Al doping: combined study of binding experiment and ab initio molecular dynamics

Al doping and defect regulation of sputtered CdZnTe films based on Al–AlN transition layers

CdZnTe films with less defects and high quality were fabricated on aluminum-rich AlN (Al–AlN) transition layers by RF magnetron sputtering technique. The Al doping and regulation effect on defect states, structure and photoelectrical performance of CdZnTe films were minutely investigated by XRD, HRTEM, SEM, XPS, Photoluminescence and Photoelectric characteristics. Results strongly suggested the self-doping process of Al from Al–AlN transition layers, which helped to compensate the defect density of Cd vacancy in CdZnTe films, thus improving crystallization, response performances and resistivity of Al-doped CdZnTe films. Electrical characterization implied the formation of good ohmic contact between electrodes and Al-doped CdZnTe films. Under 254 nm UV light illumination, the surface dark current of optimal Al-doped CdZnTe film was 25 times smaller than that of non-doped film, and rise and decay times were 3.4 and 2.8 times faster, indicating the feasibility of high quality film detectors for solar-blind UV detection.

Effect of Al-doping on morphology, structure, and optical band gap of ZnO thin films synthesized by sol–gel spin-coating technique

Effect of Al-doping on morphology, structure, and optical band gap of ZnO thin films synthesized by sol–gel spin-coating technique

Effect of (Al, Zn, Cu, and Sr) doping on structural, optical and electrical properties of sprayed SnO2 thin films

Tin dioxide thin films deposited onto a glass substrate were prepared by spray pyrolysis technique, and then doped with different elements which are: Al, Zn, Cu, and Sr by electroplating method, these elements were chosen for their different atomic radii. XRD illustrate that all the films were polycrystalline with a tetragonal rutile structure and a strong preferred orientation of (200) plane. Uv-vis spectrophotometer specters showed that the highest average transmittance of Al/SnO2 film was about 86.77% in the visible region and the Sr/SnO2 film had the highest band gap of 3.95 eV. From the MEB images, the morphological characteristics improved when the SnO2 thin films doped with Al and Zn but the opposite happened when it doped with Cu and Sr. The four-point probe showed that the best sample was for Al/SnO2 because it had the highest electrical conductivity around 692.306 (Ω.cm) -1.

Photocatalytic Water Splitting of Al-Doped RhxCr2–xO3/SrTiO3 Synthesized by Flux Method: Elucidating the Role of Different Molten Salts

Photocatalytic water splitting is a promising approach to converting solar energy into green hydrogen. As an effective photocatalyst, RhxCr2–xO3/SrTiO3 has been widely studied for water splitting, mainly synthesized using SrCl2 molten salt as the reaction media. This research systematically studied the effect of molten salts and Al doping in order to test and integrate the combinatorial effect of the modifications of SrTiO3-based catalysts. A series of SrTiO3 and Al-doped SrTiO3 (Al:SrTiO3) were synthesized by the flux method with three molten salts (NaCl, KCl, and SrCl2·6H2O) at different annealing temperatures (900 and 1000 °C). Cocatalyst, RhxCr2–xO3, was loaded on the surface of Al-doped SrTiO3 by impregnation and photodeposition methods for comparison. The photocatalytic performance of overall water splitting was evaluated in pure water under UV and AM 1.5G simulated sunlight. A significant improvement in photocatalytic activity was observed in Al-doped RhxCr2–xO3/SrTiO3. Especially Al-doped RhxCr2–xO3/SrTiO3 synthesized by KCl molten salt showed the highest hydrogen evolution rate with the synergy effect of molten salt and Al doping. Furthermore, hydrogen evolution rates were further enhanced by loading core–shell RhxCr2–xO3 using in situ photodeposition instead of impregnation, reaching 784 and 431 μmol h–1 g–1 H2 under 365 nm UV light and AM 1.5G irradiation, respectively.

Enhanced dielectric and energy storage performances of Hf0.6Zr0.4O2 thin films by Al doping

Hf- and Zr-based oxide thin films, which have various polarization characteristics depending on the crystal structure, have been intensively studied for application in various semiconductor devices due to their excellent electrical properties and complementary metal oxide semiconductor process compatibility. Especially, when the tetragonal phase is implemented, they exhibit a high dielectric constant with anti-ferroelectric properties. Therefore, in this study, the effect of Al doping in HfZrO2 thin films was investigated from the viewpoint of the realization of a high dielectric constant and a stable anti-ferroelectric phase. Through a small amount of Al doping, the crystal structure was modulated from monoclinic to tetragonal. Also, the polarization characteristics were observed in the change of ferroelectric to anti-ferroelectric. Owing to the formation of a tetragonal structure, the dielectric constant was improved up to 41, and the leakage current density remarkably decreased by more than one order of magnitude. Moreover, the Al-doped HfZrO2 thin film with anti-ferroelectricity exhibited excellent energy storage properties with an energy storage density and efficiency of about 53.3 J/cm3 and 76% at ±4.5 MV/cm, respectively. Therefore, we propose that Al-doped HfZrO2 thin film could be applied as a candidate material for next-generation charge storage devices.

Effect of Al and La Doping on the Structure and Magnetostrictive Properties of Fe73Ga27 Alloy

The changes of microstructure, magnetostriction properties and hardness of the Fe73Ga27-xAlx alloy and (Fe73Ga27-xAlx)99.9La0.1 alloy (x = 0, 0.5, 1.5, 2.5, 3.5, 4.5) were studied by doping Al into the Fe73Ga27 and (Fe73Ga27)99.9La0.1 alloy, respectively. The results show that both the Fe73Ga27-xAlx alloy and (Fe73Ga27-xAlx)99.9La0.1 alloy are dominated by the A2 phase, and the alloy grains are obvious columnar crystals with certain orientations along the water-cooled direction. A proportion of Al atoms replaced Ga atoms, which changed the lattice constant of the alloy, caused lattice distortion, and produced vacancy effects which affected the magnetostriction properties. La atoms were difficult to dissolve in the matrix alloy which made the alloy grains smaller and enhanced the orientation along the (100) direction, resulting in greater magneto-crystalline anisotropy and greater tetragonal distortion, which is conducive to improving the magnetostriction properties. Fe73Ga24.5Al2.5 alloy has a saturation magnetostrictive strain of 74 ppm and a hardness value of 268.064 HV, taking into account the advantages of saturated magnetostrictive strain and high hardness. The maximum saturation magnetostrictive strain of the (Fe73Ga24.5Al2.5)99.9La0.1 alloy is 115 ppm and the hardness is 278.096 HV, indicating that trace La doping can improve the magnetostriction properties and deformation resistance of Fe-Ga alloy, which provides a new design idea for the Fe-Ga alloy, broadening their application in the field of practical production.