Aluminum Doping Research Articles

Different Grain Sizes of $${\mathrm{{MgAl}}_2\mathrm{{O}}_4}$$ Doped Alumina and Its Influence on SPD, CDBD, and APTD

Different Grain Sizes of $${\mathrm{{MgAl}}_2\mathrm{{O}}_4}$$ Doped Alumina and Its Influence on SPD, CDBD, and APTD

Efficient Photocatalytic Hydrogen Evolution via Cocatalyst Loaded Al-doped SrTiO3

The growing reliance on fossil fuels is causing significant environmental issues, prompting the search for renewable energy sources. Hydrogen energy, which produces only water vapor, is a promising solution. This study focuses on developing an aluminum-doped SrTiO3 photocatalyst with dual cocatalysts (Rh/Cr2O3 and CoOOH) for efficient photocatalytic water splitting. Using a simple chemical deposition method, high-purity and crystalline SrTiO3 was synthesized and thoroughly characterized. The results show that the modified SrTiO3 achieved significantly higher photocatalytic activity, with Rh/Cr2O3/SrTiO3@Al/CoOOH producing 11.04 mmol g–1 h–1 of H2 and 4.69 mmol g–1 h–1 of O2. This work demonstrates the effectiveness of dual cocatalyst deposition and aluminum doping in enhancing photocatalytic performance by improving charge separation and reducing recombination.

Specifics of Al substitution into boron carbide: A DFT study

Boron carbide (B4C), known for its hardness and low density, is prone to local amorphization under high non-hydrostatic loads, limiting its applications. Aluminum doping is promising due to aluminum's atomic size, fitting into the B4C crystal lattice, particularly the intericosahedra chain, potentially reducing amorphization. This work uses first-principles calculations to study aluminum placement in B4C. We examine the potential for Al substitution in the icosahedron and intericosahedra chain, identifying possible locations. Results show that aluminum can't replace atoms in the icosahedron, but substituting one central atom in the intericosahedra chain with aluminum is energetically favorable and likely changes the chain configuration to an angular one. Additionally, aluminum can substitute one carbon in the (C-B-C) chain of B12(C-B-C) boron carbide. Comparative analysis suggests these configurations may coexist. Our study offers a theoretical model that can guide future experimental efforts and provides valuable insights into the structural specifics of aluminum-doped boron carbide.

Investigating the influence mechanism of aluminum doping amount on the density and grain size of AZO target through phase-field simulation

This study proposes a three-phase model (primary, secondary, and pore phases) utilizing the phase-field method to simulate sintering densification in AZO targets. The impact of secondary phase content and dimensions on the densification of AZO targets was investigated. The findings indicated that the density of the AZO target exhibited an initial increase followed by a subsequent decline with the augmentation of the secondary phase content and size. Conversely, the grain size demonstrated a continuous reduction. The Brook kinetic equation yields activation energies for grain growth of 607.40kJ/mol, 999.32kJ/mol, and 1093.20kJ/mol for 1wt%, 2wt%, and 3wt% Al2O3, respectively. Furthermore, the viability of the model was corroborated through experimentation. Based on the simulation outcomes, AZO targets doped with 2wt% Al₂O₃ achieved 99.78% densification, an average grain size of 3.92 μm, and a resistivity of 1.38 mΩ·cm.

An Effect of Al on the Properties of ZnIn2Se4 Thin Film

Abstract Zinc-indium-selenide ZnIn2Se4 (ZIS) ternary chalcopyrite thin film on glass with a 500 nm thickness was fabricated by using the thermal evaporation system with a pressure of approximately 2.5×10−5 mbar and a deposition rate of 12 Å/s. The effect of aluminum (Al) doping with 0.02 and 0.04 ratios on the structural and optical properties of film was examined. The utilization of X-ray diffraction (XRD) was employed to showcase the influence of aluminum doping on structural properties. XRD shows that thin ZIS-pure, Al-doped films at RT are polycrystalline with tetragonal structure and preferred (112) orientation. Where the degree of crystallinity is raised. The effect of Al content on surface roughness and average diameter was studied by atomic force microscopy (AFM), which showed that both surface roughness and average diameter increased with an increasing Al ratio until they reached their maximum values of 12.93 nm and 61.56 nm, respectively. Optical characteristics of ZIS thin film and the impact of aluminum on optical parameters have been investigated, and it was found that the optical energy ( E g opt ), absorption coefficient (α), extinction coefficient (k), refractive index (n), both the real (εr) and imaginary (εi) components of the dielectric constant have values of (1.8 eV), (3.11×104 cm−1), (0.111), (2.3), (5.36), and (0.517), respectively, for ZIS thin films at an Al ratio equal to 0.04.

First-principles study of BC3 monolayer for sensing halomethanes: a computer aided investigation

This research used a method called DFT to study how CH3Br, CH3Cl, and CH3F halomethanes stick to boron carbide (BC3) nanosheets, with and without gallium and aluminum doping. Geometric optimisation was conducted for all structures using the B3LYP/6-311 + G (d) method. Furthermore, three different methods were employed to calculate the energy: M06-2X, ωB97X-D3, and CAM-B3LYP/6-311 + G(d). NBO and the QTAIM analysis was conducted to evaluate the WBI, partial natural charge, and donor–acceptor interactions within the molecules. The adsorption energy results showed that adding gallium to BC3 made it best at adsorbing stuff, while BC3 without any additives absorbed the least. However, CH3Cl stuck best to the aluminum-doped BC3 and least to the plain BC3 because it had less energy holding onto it. Also, CH3Br stuck to the nanosheet surfaces the most, while CH3Cl stuck the least. BC3(Ga)NS was discovered to be better at detecting halomethanes than BC3(Al)NS and BC3NS. Also, when the halomethanes were absorbed, the doped nanosheets experienced big changes in their electronic behaviour. The energy gaps for BC3NS, BC3(Al)NS, and BC3(Ga)NS were found to be 3.5%, 15.2%, and 13.6%, respectively. Gallium and aluminum mixed with BC3 seem good for making new sensors to detect halomethanes.

Investigating the Role of Aluminum Doping on the Bandgap Modulation and Photocatalytic Efficiency of Strontium Nickel Ferrites for Ciprofloxacin Degradation

Investigating the Role of Aluminum Doping on the Bandgap Modulation and Photocatalytic Efficiency of Strontium Nickel Ferrites for Ciprofloxacin Degradation

X-ray-induced long persistent luminescence of Cu+-doped high alumina borosilicate glass

A Cu+ doped high alumina borosilicate glass with long persistent luminescence (LPL) was prepared by reduction melting and radiation induction based on glass defect engineering. The maximum time of the persistent luminescence can arrive 16 h. Spectral and EPR measurements indicate that two kinds of oxygen defects can be induced by X-ray radiation. One defect was eliminated after UV irradiation, and the other can synergistically participate in the LPL process of glass with reduction induced oxygen deficiency centers(ODCs). In addition, there is a highly linear relationship between the initial LPL intensity of the glass and the radiation dose; which implies the glass can be used as a radiation detection material. The internal mechanism of the linear relationship and LPL was discussed.

Optimizing ZnO as an electron transport layer in perovskite solar cells: Study on aluminum doping and thickness variation

Optimizing ZnO as an electron transport layer in perovskite solar cells: Study on aluminum doping and thickness variation

Zn-Al Ferrite/Polypyrrole Nanocomposites: Structure and Dielectric and Magnetic Properties for Microwave Applications.

In this study, Zn-Al ferrite/polypyrrole (PPy) nanocomposites were synthesized and thoroughly characterized to explore their potential for microwave applications. X-ray diffraction analysis confirmed the presence of ZnO, AlFeO3, and Fe2O3 phases, with the crystal size decreasing from 31 nm to 19.6 nm as aluminum content increased. High-resolution transmission electron microscopy (HR-TEM) revealed a distinctive core-shell morphology, where the polypyrrole encapsulates the ZnAlxFe2-xO4 particles. Magnetic measurements showed that decreasing aluminum concentration led to a reduction in both saturation magnetization (Ms) from 75 emu/g to 36 emu/g and remanent magnetization (Mr) from 2.26 emu/g to 2.00 emu/g. Dielectric analysis indicated that both the real (ε') and imaginary (ε″) components of dielectric permittivity decreased with increasing frequency, particularly between 10 and 14 GHz. Furthermore, electrical modulus analysis highlighted the significant impact of aluminum doping on relaxation time (τIP), indicating the presence of interface polarization. Impedance spectroscopy results underscored the dominance of interface polarization at lower frequencies and the presence of strong conduction paths at higher frequencies. These combined magnetic and dielectric loss mechanisms suggest that the Zn-Al ferrite/polypyrrole nanocomposite is a promising candidate for advanced microwave absorption applications.

Impacts of ultraviolet absorption by zinc oxide nanoparticle modifiers on asphalt aging

Ultraviolet absorption ability of modifiers is essential to protect asphalt from ageing. However, the detailed correlation between them remains unclear. In this study, zinc oxide nanoparticles were used as modifiers, and their ultraviolet absorption ability was manipulated by magnesium and aluminum doping. The influence of ultraviolet absorption ability of the nanoparticles on asphalt ultraviolet ageing was investigated experimentally, and their correlation was revealed in detail by curve fitting. The results show that aluminum doping enhances the ultraviolet absorption ability of nanoparticles, leading to superior anti-aging performance in aluminum-doped zinc oxide modified asphalt compared to pure zinc oxide. Conversely, magnesium doping shows a contrary modification. Evaluating the ultraviolet absorption ability of nanoparticle modifiers by bandgap and absorption intensity, we found that softening point increments, viscosity ageing index, and sulfoxide index exhibit a decreasing trend mainly in the bandgap range of 3.269 to 3.334 eV, whereas carbonyl index shows a decreasing trend mainly in the lower bandgap range of 3.183 to 3.269 eV. This phenomenon is primarily due to the different reactivity of carbon and sulfur with oxygen in asphalt. Curve fitting analysis revealed an exponential correlation between the ageing index of asphalt and the ultraviolet absorption ability of nanoparticles. To achieve superior anti-ultraviolet ageing performance, the nanoparticles should possess an absorption intensity above 0.961 a.u. and a bandgap below 3.299 eV. Moreover, stronger ultraviolet absorption ability of nanoparticles is needed to prevent the formation of carbonyl compounds. The underlying correlation established in the present work has significant implications for selecting suitable modifiers to prevent ultraviolet ageing of asphalt.

Over 10% efficient Cu2ZnSn(S, Se)4 Thin-Film cells prepared by aluminium doping

Cu2ZnSn(S,Se)4(CZTSSe) solar cell is of excellent development tendency because of lower pollution and outstanding power conversion efficiency(PCE). Yet, current PCE of CZTSSe is limited because of a high open-circuit voltage deficit, primarily put down to severe band tailing and carrier recombination. In this paper, absorber films were obtained by solution method and the influences of different aluminum doping concentrations on the properties of CZTSSe thin film cell were studied. Analysis about X-ray diffraction (XRD) and Raman spectroscopy confirms which Al has incorporated into CZTSSe thin film lattice and replaced Sn. Hall effect measurements reveal the improvement of carrier concentration on thin film absorber layer attribute to the formation of AlSn acceptor defects. Furthermore, X-ray photoelectron spectroscopy (XPS) reveals that Al enter into the CZTSSe lattice and Al is in the appropriate state of + 3 valence without generating additional harmful defects. More important, the generation of deep energy level defects and defect clusters associated with Sn were suppressed by replacing Sn with Al. Finally, the photovoltaic performance of different Al doped CZTSSe cells were characterized by conducting J-V and external quantum efficiency (EQE) tests. Remarkably, the CZTSSe solar cell with PCE as high as 10.59 % is obtained under a doping level of 6 % Al, which has an open circuit voltage of 522 mv. Compared with reference CZTSSe solar cells with an efficiency of 7.29 %, which indicates with improvement of 45 % in efficiency. Consequently, Al doping process is considered as a prospective tactic to elevate the PCE of CZTSSe solar cells.

The Effect of Concentration of Aluminum on Structural, Optical, and Electrical Properties of Aluminum‐doped ZnO Nanostructures Electrochemically Deposited on Polyimide

AbstractAluminum‐doped ZnO (AZO) were successfully prepared on polyimide (PI) film using electrochemical deposition. Field emission scanning electron microscopy (FESEM) analysis revealed that as the aluminum concentration increased, the morphology of AZO nanostructures changed from pellets to nanorods. X‐ray photoelectron spectrometry (XPS) was employed to study the chemical states of undoped and Al‐doped ZnO on a polyimide substrate. The X‐ray diffraction (XRD) patterns of the PI/AZO nanostructures showed a polycrystalline wurtzite structure with a crystallographic orientation along the (002) plane. The XRD analysis also indicated that the average crystallite size decreased from 50.5 nm to 31.0 nm with increasing aluminum concentration (from 0.05 mM to 10 mM). Transmittance analysis revealed that with increasing aluminum concentration, the average optical transmittance in the visible region decreased from 90 % to 75 %. The aluminum concentration has a significant effect on the electrical properties of the samples, as shown by current‐voltage (I–V) and Hall measurements. Among the samples, the AZO/PI film prepared with 5 mM aluminum concentration exhibited the minimum electrical resistivity (4.14×10−2 Ω.cm), the highest carrier density (1.10×1021 cm−3) and the Hall mobility (5.40 cm2 V−1 s−1). We also discuss the possible mechanisms underlying these results compared to undoped ZnO films. This study contributes to the potential applications in flexible electronics and optoelectronics by demonstrating the tunability of AZO nanostructures on a flexible polyimide substrate through controlled aluminum doping.

The Effect of Aluminum Dopant on some physical Properties of Zinc Oxide Thin Films Via Chemical Spray Pyrolysis

تم حضرة أوكسيد الخارصين باستخدام طريقة التحلل الكيميائي الحراري وبتراكيز مختلف من شائبة الألمنيوم (0، 2، 4) %. كشفت أنماط حيود الاشعة السينية بان كافة الاغشية المحضرة كانت من النوع متعدد التبلور سداسي، متراض التركيب، تتراوح قيم الحجم الحبيبي من 13.30 نانومتر إلى 14.34 نانومتر مع زيادة تركيز الالمنيوم، أوضحت صور مجهر القوى الذرية بان الاغشية كانت منتظمة، خالية من التشققات ولها معدل حجم الجسميات في مدى (84.27 -72.18) نانومتر. وجد بان أطياف النفاذية لها معدل بحدود 85%. انحرفت قييم فجوة الطاقة باتجاه الطاقات الواطئة بزيادة شائبة الالمنيوم.

Linear Conductance Modulation in Aluminum Doped Resistive Switching Memories for Neuromorphic Computing

Linear Conductance Modulation in Aluminum Doped Resistive Switching Memories for Neuromorphic Computing

Plasmonic Al, Ga and in-doped zinc oxide nanoparticles as key components for the design of electrophoretic inks with MWIR and LWIR absorbance properties

Doped zinc oxide nanocrystals (NCs) are halfway through semiconductors and metals. They exhibit unique optoelectronic properties from a high surface density of free-charge-carriers, which are responsible for localized surface plasmon resonance (LSPR). Here, a one-pot approach is presented to synthesize doped aluminum, gallium or indium zinc oxide NCs, making them all stable in non-polar media. The effect of doping on the growth mechanisms and the final crystalline structure were studied as a function of the aliovalent doping atom used. Doping atoms were integrated by substitution of Zn atom into the crystalline mesh of ZnO with a wurtzite phase identified as the primary crystalline phase for all samples by X-ray Diffraction (XRD). Typical aluminiun doped ZnO NCs (AZO) or Gallium doped NCs (GZO) nanoflowers were identified as a single crystalline structure by High-Resolution-Transmission Electron Microscopy (HR-TEM). Indium doped ZnO NCs (IZO) and pristine ZnO appeared significantly different with spherical and heart-like shapes, respectively. The doping level tendency was identified through Energy Dispersive X-ray (EDX) and increased form Al to Ga and In doping atoms. All plasmonic doped NCs have broadband infrared absorption in the Middle-wave (MWIR) and Long-wave infrared (LWIR) wavelengths, making them interesting for thermal regulation or thermal camouflage. As part of the latter application, dispersions of doped ZnO NCs were formulated as electrophoretic inks and their IR-absorbing performances determined by using a homemade setup including an infrared camera. AZO, GZO, and IZO NCs based inks achieved temperature contrasts of 15 °C and 6 °C in the MWIR and LWIR wavelengths.

Geometric and Electronic Properties of P Atom-Doped Al Nanoclusters: Alkaline-like Superatom of P@Al12.

The geometric and electronic characteristics of phosphorus-atom doped aluminum nanoclusters, AlnPm (n = 7-17, m = 1 and 2), were investigated through a combination of experiments and theoretical calculations. The size dependences of the ionization energy (Ei) for AlnPm NCs exhibit a local minimum of 5.37 eV at Al12P1, attributed to an endohedral P@Al12 superatom (SA). This SA originates from an excess electron toward the 2P shell closing (40e), coexisting with an exohedral isomer featuring a vertex P atom. The stability of the endohedral P@Al12 is further enhanced in its cationic state compared to the exohedral isomer, when complexed with a fluorine (F) atom, forming an SA salt denoted as P@Al12+F- with an elevated Ei ranging from 6.42 to 7.90 eV. In contrast, for the anionic Al12P1-, the exohedral form is found to be more stable than the endohedral one using anion photoelectron spectroscopy and calculations. The geometric and electronic robustness of neutral P@Al12 SAs against electron donation and acceptance is discussed in comparison to rare-gas-like Si@Al12 SAs.

Exploring the effects of molecular beam epitaxy growth characteristics on the temperature performance of state-of-the-art terahertz quantum cascade lasers

This study conducts a comparative analysis, using non-equilibrium Green’s functions (NEGF), of two state-of-the-art two-well (TW) Terahertz Quantum Cascade Lasers (THz QCLs) supporting clean 3-level systems. The devices have nearly identical parameters and the NEGF calculations with an abrupt-interface roughness height of 0.12 nm predict a maximum operating temperature (Tmax) of ~ 250 K for both devices. However, experimentally, one device reaches a Tmax of ~ 250 K and the other a Tmax of only ~ 134 K. Both devices were fabricated and measured under identical conditions in the same laboratory, with high quality processes as verified by reference devices. The main difference between the two devices is that they were grown in different MBE reactors. Our NEGF-based analysis considered all parameters related to MBE growth, including the maximum estimated variation in aluminum content, growth rate, doping density, background doping, and abrupt-interface roughness height. From our NEGF calculations it is evident that the sole parameter to which a drastic drop in Tmax could be attributed is the abrupt-interface roughness height. We can also learn from the simulations that both devices exhibit high-quality interfaces, with one having an abrupt-interface roughness height of approximately an atomic layer and the other approximately a monolayer. However, these small differences in interface sharpness are the cause of the large performance discrepancy. This underscores the sensitivity of device performance to interface roughness and emphasizes its strategic role in achieving higher operating temperatures for THz QCLs. We suggest Atom Probe Tomography (APT) as a path to analyze and measure the (graded)-interfaces roughness (IFR) parameters for THz QCLs, and subsequently as a design tool for higher performance THz QCLs, as was done for mid-IR QCLs. Our study not only addresses challenges faced by other groups in reproducing the record Tmax of ~ 250 K and ~ 261 K but also proposes a systematic pathway for further improving the temperature performance of THz QCLs beyond the state-of-the-art.

Raman deconvolution, radiation shielding, TL effective and dielectric investigations of Dy3+ doped alumina lead borate glasses

The objective of the current investigation was to create radiation-shielding materials that possess both thermally luminous, and dielectric behaviour. Subsequently, a glass series of Al(20-x)Pb10B70:Dyx materials was fabricated (where, x ≤ 2.5 and 0 ≤ x ≤ 1.5 in increments of 0.1, 0.5, 1, 1.5, 2, and 2.5 mol %). These materials were characterized structurally (utilizing Raman, FT-IR, DTA, SEM, XRD, and EDX), thermoluminescence, and dielectric properties. The SEM and XRD analyses demonstrate vitreous behavior. The EDX analysis provides atomic weight percent values for the chemical components. The glasses' physical properties were assessed, including their molar volume (approximately 37.48 cm3 mol−1) and density (approximately 2.725 gm/cm3). The DTA analyses of glasses indicate that the changes in GTT (approximately 286 °C) and thermal stability (∼0.656) are solely attribute to Dy3+ ions. An assortment of structural vibrations of the test glass are verified through the utilization of FT-IR and Raman analyses. The evaluation of the test glasses' micro-hardness (<5.26 GPa) was conducted utilizing ultrasonic velocities. The RPE (approximately 33.17 %) and MAC (16.9 g/cm3) indicate that the shielding behavior is also function of Dy3+ ions. The TL properties are investigated within the dose range of 5, 10, and 25 kGy of gamma irradiation. The frequency factor (3.025 × 1021 S−1) and A.E. (∼1.766 eV) of the glasses evaluated. The TL behavior of glasses is also noticed as a function of Dy3+ ions. The dielectric properties of the glasses are also analysed. The dielectric parameters such as dielectric constant (7.98), dielectric loss (0.021), ac conductivity (0.671 × 10−8 Ω−1cm−1), and A.E. (1.139 eV) evaluated. The results which include structure, elastic, radiation shielding, thermoluminescence and dialectic studies of Al(20-x)Pb10B70:Dyx glasses suggesting the glasses developed are mechanical hard, TL effective, and serve as radiation shielding dielectric resource.

Fully atomic layer deposition induced InAlO thin film transistors

The atomic layer deposition (ALD) technique has been extensively utilized for depositing metal oxide (MO) thin films, particularly as gate insulators in thin film transistors (TFTs). However, research on MO semiconductors as channel layer materials in TFTs using ALD is limited, especially for fully ALD-fabricated MO TFTs. In this study, fully ALD-fabricated InAlO TFTs were developed, with optimized aluminum doping content and annealing temperature to enhance the electrical properties and stability. The InAlO TFTs, fabricated with a cycle ratio of 15:1 and annealed at 350 °C, exhibit superior performance, including a field-effect mobility of 7.2 cm2/V·s, a subthreshold swing of 165 mV/decade, and an on/off current ratio of 2.3 × 106, with a threshold voltage of only 0.1 V. Additionally, they demonstrated good stability, with a threshold voltage shift of 0.11 V under positive bias stress. The improved electrical properties and stability are attributed to reduced carrier concentration and the inhibition of oxygen defect generation, achieved through appropriate annealing temperatures and aluminum doping. Thus, the development of fully ALD-fabricated high-performance TFTs holds promise for next-generation display technologies as pixel-driving circuits.