Mg-doped ZnO Research Articles

Impact of modified spin coating variations on electrical resistivity and UV detector responsivity in Mg-doped ZnO thin films

This study addresses the impact of different spin coating speeds on the optical, structural, and electrical properties of the Mg doped ZnO films for UV detectors. XRD demonstrated that as the spin rate increased from 1000 to 3000 rpm, the film's crystallinity decreased from 35.66 to 15.74 nm. Increasing the rotation speeds from 2500 to 3000 rpm caused a shift towards lower 2θ values in the peak (101) of Mg doped ZnO thin films due to lattice contraction. SEM analysis reveals that spin coating speed results in a smoother surface, featuring a wrinkle pattern (2500 and 3000 rpm). The thickness of the thin films decreases significantly, from 608 nm to 240 nm. AFM measurements indicated a decrease in surface roughness from 78.12 nm to 18.9 nm. The optical properties of the higher spin coating speed show 96% transmittance. UV–Vis spectroscopy shows the absorption edge in the range 330–340 nm. The energy bandgap value increased from 3.13 eV to 3.37 eV. The vibrational peaks at 435 cm⁻1 and 350 cm⁻1 in the Raman spectra confirm the wurtzite structure of ZnO and the multi-phonon process. The examination of electrical properties via I–V characteristic curves reveals an ohmic behavior. The carrier concentration increased from 0.96 × 1014 cm−3 to 5.66 × 1014 cm−3, and the resistivity values decreased from 9.45 × 103 Ω cm to 1.10 × 103 Ω cm in Mg doped ZnO films. At 3000 rpm, the responsivity reaches 10.2 mA/W. This shows faster spin coating rates lead to higher responsivities, leading to better performance of the UV detector.

An Assay on the Antibactericidal Functionality of Synthesized Mg-Doped ZnO Nanoparticles on the DentalMicrobes.

We succeeded in producing pure and magnesium-doped zinc oxide nanoparticles (Mg-Zn NPs) by making use of a Prosopis farcta leaf extract and subsequently distinguished the quality of our NPs with the use of field energy scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), powder X-ray diffraction (PXRD), and UV-vis. In correlation to our observations, the particulates were spherically produced at a size of 20 nm with the ability to cause antimicrobial impacts on Streptococcus mutans bacteria and Candida albicans fungi. Inhibition zones of 18 ± 0.3 and 24 ± 0.3 mm were obtained for 5% Mg-Zn NPs against bacteria and fungi, respectively. Based on these results, our work suggests a practicable proposition for our synthesized product to be considered as a worthy alternative for dental and oral utilizations.

Effect of magnesium doping on the structure, optical properties and photocatalytic efficiency of ZnO nanostructures deposited by atmospheric pressure MOCVD

ZnO nanostructures doped by magnesium impurity were grown on Si substrates by atmospheric pressure MOCVD deposition using Zn and Mg acetylacetonates as initial precursors. XRD patterns confirm the successful incorporation of Mg ions into ZnO lattice. Room-temperature photoluminescence spectra of Mg-doped ZnO nanostructures demonstrate near-band edge emission and visible deep-level emission with ratios 2.9, 1.3 and 0.3 correspondingly for 1, 2.4 and 5.7 at. % of Mg in ZnO nanostructures. Raman measurements showed decreasing in intensity for ZnO modes with increasing Mg content. The best photodegradation rate constant was observed for ZnO NS with 2.4 at. % of Mg.

Enhanced UV photodetector using Mg-doped ZnO sub-micro tube films synthesized through laser-assisted chemical bath growth

This study presents the fabrication of MgxZn(100-X)O thin films (TFs) with Mg concentration levels (x) of 0.5 at%, 1.0 at%, 1.5 at%, and 2.0 at% on glass substrates using the novel laser-assisted chemical bath growth (LACBG) method, aimed at investigating their photo-response for potential UV photodetector applications. Utilizing a continuous wave semiconductor laser with a 444.5 nm wavelength, 1 W power, and 6 min of irradiation, the LACBG method successfully produced high-quality Mg-doped ZnO TFs. These films were deposited on glass substrates coated with silver (Ag) to serve as electrode contacts for constructing a metal-semiconductor-metal (MSM) UV photodetector. The structural, optical, and electrical properties of the TFs were thoroughly analyzed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to examine the crystal microstructures and surface morphologies, revealing vertically aligned hexagonal symmetrical sub-micro tubes. In contrast, energy dispersive X-ray (EDX) analysis confirmed successful Mg incorporation into the ZnO lattice. UV–visible absorbance spectra indicated a blue shift in the absorption edge and increased band gap energy from 3.24 eV to 3.67 eV with rising Mg content. The UV photodetectors, particularly those with 2.0 at% Mg-doped ZnO TFs, demonstrated significantly enhanced UV responsiveness attributed to optical confinement, high surface-to-volume ratio, and superior structural quality. Performance metrics for the 2.0 at% Mg-doped ZnO TFs included a responsivity of 10.60 A/W, external quantum efficiency of 34.10, specific detectivity of 2.25 × 107 Jones, noise equivalent power of 5.34 × 10−11 W, rise time of 86.9 ms, and decay time of 324.4 ms. These findings underscore the potential of Mg-doped ZnO TFs for high-performance UV photodetection applications. The novelty of this study lies in utilizing LACBG to achieve high-quality Mg-doped ZnO TFs, offering a cost-effective, low-temperature method that enhances UV photodetector performance.

Enhanced UV photodetector performance using sputtered Mg-doped ZnO thin film

In this article, we demonstrate UV photodetector synthesized using Mg-doped ZnO thin film (TF) (10 % Mg) grown on a p-Si substrate using the radio frequency (RF) magnetron sputtering system. The fabricated MgZnO TF was annealed at 500 °C in air resulting in notable changes in morphology, optical band gap and crystallinity that significantly improved the UV light sensitivity. The annealed device (MgZnO TF/p-Si) exhibited a remarkable 155-fold increase in photocurrent density compared to the as-deposited device at + 2 V bias. Also, at the same bias the annealed device (500 °C) exhibited high photosensitivity (up to 1262 times), responsivity (20.32 A/W), specific detectivity (1.82 × 1013 Jones) and external quantum efficiency (EQE) (7745 %) in comparison to the as-deposited device. Additionally, the 500 °C device achieved a low noise equivalent power (NEP) of 0.07 × 10−12 W which is about 262 times lower than that of the as-deposited device (18.4 × 10−12 W). Furthermore, on UV illumination (λ = 325 nm) the MgZnO TF/p-Si (500 °C) detector showed fast device response with rise time/fall time values of 0.26 s/0.25 s respectively at + 2 V applied bias.

Synthesis and Characterization of Mg-doped ZnO Nanoparticles for Gas-sensing Applications

Synthesis and Characterization of Mg-doped ZnO Nanoparticles for Gas-sensing Applications

Wedge-shape Al and Mg co-doped zinc oxide thin films: A Facile Route to achieve high thermoelectric power factor

Thin film thermoelectric technology has immense potential to become a next-generation power source for small-scale electronics. However, the rapid development of thin film thermoelectric still lacks a controllable structural design to improve the performance of thermoelectric devices for required temperature applications. This work presented a controlled thermoelectric design of ZnO-based thin films by Al and Mg co-doping using ALD. Herein, the Mg-doped ZnO sample exhibits the highest Seebeck coefficient of −311.83 μVK−1 at 500oC, while the maximum thermoelectric power factor of 3.68 μWcm−1K−2 is obtained at 300oC, which drops for higher temperatures. This decrease in power factor resulted from the reduction in electrical conductivity above 300oC. Similarly, the Al and Mg co-doped ZnO sample (Mg/Al ≈2 at%) exhibits a high thermoelectric power factor of 3.85 μWcm−1K−2 for ZnO based material due to its moderate electrical conductivity and Seebeck coefficient value at 325oC and behave monotonically for elevated temperatures. Scanning electron microscope (SEM) images show the formation of wedge-shaped structures for Al-incorporated samples, which helps to boost the overall thermoelectric performance. Additionally, we performed XRD, UV–Vis, Hall, and AFM analysis to get a deep insight into structural, optical, electrical, and surface features of the grown thin films and their linkage with the thermoelectric properties.

Biomedical Applications of Green Synthesized Zinc Oxide and Magnesium-Doped Zinc Oxide Nanoparticles Using Aqueous Extract of Ziziphus Oxyphylla Leaves.

Zinc oxide (ZnO) and magnesium-doped zinc oxide (Mg-doped ZnO) nanoparticles (NPs) were synthesized using Ziziphus oxyphylla 's aqueous leaf extract as reducing agent. UV-Vis absorption peaks at 324 nm and 335 nm were indicative of ZnO and Mg-doped ZnO, respectively. FTIR absorption bands observed at 3238, 1043, 1400, 1401, 2186 and 2320 cm -1 suggested the presence of phenols, alcohols, saturated hydrocarbons, and possibly alkynes. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy revealed pure, spherical and agglomerated NPs with average size of 35.9 nm (ZnO) and 56.8 nm (Mg-doped ZnO). Both NPs remained active against all bacterial strains with the highest inhibition zones observed against Proteus vulgaris (21.16±1.25 mm for ZnO and 24.1±0.76 mm for Mg-doped ZnO. EtBr fluorescence (cartwheel assay) indicated efflux pump blockage, suggesting its facilitation in the bacterial growth inhibition. Antioxidant potential, determined via DPPH radical scavenging assay, revealed stronger antioxidant potential for Mg-doped ZnO (IC [Formula: see text]/mL) than pure ZnO (IC [Formula: see text]/mL). Furthermore, both NPs showed antileishmanial activity against Leishmania tropica promastigotes (IC [Formula: see text]/mL for Mg-doped ZnO and 64.34±6.56 for ZnO), while neither NP exhibited significant hemolysis, indicating biocompatibility and further assessment for their drugability.

Mg-doped ZnO thin film based capacitive memory with low leakage current

Mg-doped ZnO thin film based capacitive memory with low leakage current

The effects of nitrogen ionization during preparation and oxygen pressure during annealing on the morphology, structure, and luminescent properties of Mg-doped ZnO thin films

The effects of nitrogen ionization during preparation and oxygen pressure during annealing on the morphology, structure, and luminescent properties of Mg-doped ZnO thin films

Mg-doped ZnO nanoparticle as an effective nanocarrier in delivery of 5-Fluorouracil anti-gastric cancer drug

5-Fluorouracil (5-FU) is a chemotherapy drug that belongs to a class of medications known as antimetabolites and has many applications in cancer therapy, especially in the treatment of gastric cancer. However, high dose of 5-FU in gastric cancer treatment can cause various side effects. Therefore, delivery of this significant drug with a suitable delivery system can significantly improve the safety and efficacy of this drug, leading to better treatment outcomes and improved patient quality of life. Mg-doped ZnO has garnered significant attention in scientific research due to its distinct physicochemical characteristics. This investigation introduces an uncomplicated and economical approach for synthesis of Mg-doped ZnO nanoparticles. Then, the nanoparticles were subjected to thorough analysis employing FT-IR, XRD, XPS, FE-SEM, TEM, UV–Vis, EDS, and DLS techniques. Subsequently, the research explored capacity of the created nanostructure to serve as a nanocarrier for 5-Fluorouracil. Findings indicated an approximately 76 % drug loading capacity that is dependent on pH and duration time. The release profile depicted a gradual release under physiological conditions (pH 7.4, 39 %), contrasting with a notably accelerated release rate at pH 5.3 (82 %) in 48 h. Furthermore, an in vitro assessment of cellular cytotoxicity performed on AGS gastric cancer cell line to evaluate safety and effectiveness of Mg-doped ZnO nanoparticles. Results from MTT assay affirmed the potential of this nanoparticle as a promising vehicle for 5-Fluorouracil delivery.

Impact of Mg‐doping on morphology, structure, optical properties, and enhancing photocatalytic performance of ZnO thin films, prepared by sol–gel spin‐coated method

AbstractThin films of pure and Mg‐doped ZnO (MZO) were successfully fabricated on glass substrates by sol–gel spin coating method. Microstructure, surface morphology, elemental composition, optical analysis, and Mg doping effect on the photocatalytic performance of the thin films have been measured by XRD, SEM, EDS, and UV–Vis, respectively. XRD analysis showed that ZnO and MZO thin films have a hexagonal wurtzite structure, and the intensity of the (0 0 2) peak moved from higher to lower angle and right to left with rising Mg‐dopant concentration, and crystallinity was enhanced with doping, whereas micro‐strain and dislocation density dropped. SEM analysis found that ZnO had spherical and agglomerated structures, and the increased size of the grains was observed with increasing doping. The optical analysis demonstrated that the band gaps increased as the dopant percentage increased. Methylene blue, a dye pollutant, examined the thin films’ photocatalytic performance. It was demonstrated that the addition of the Mg to the ZnO lattices increased the absorption of the hydroxyl ions at the surface of the thin film and hence acted as a trap site, leading to a decrease in the electron–hole pair and consequently enhancing the photodegradation.

Bifunctional Applications of Facile Mg-doped ZnO Nanoparticles Fabricated Via Co-precipitation Technique

Bifunctional Applications of Facile Mg-doped ZnO Nanoparticles Fabricated Via Co-precipitation Technique

OPTICAL PROPERTIES AND ANTIBACTERIAL ACTIVITY OF Ni, Mg, AND Fe-DOPED ZnO

In recent years, research on pure ZnO, Ni-doped ZnO, Mg-doped ZnO, and Fe-doped ZnO nanostructures has been gradually progressing to create more effective materials that may be applied in a variety of applications. In this investigation, hydrothermal synthesis was used to create both pure ZnO nanoparticles and ZnO that had been doped with Ni, Mg, and Fe at a concentration of 7%. Before testing the nanostructures’ ability to inhibit harmful bacteria (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Enterobacter sp.), they were shown to have antibacterial activity. With the use of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and ultraviolet–visible (UV–Vis), their physicochemical characteristics were initially determined. When Ni, Mg, and Fe are inserted into ZnO, XRD measurements show that the particle size decreases from 28.94[Formula: see text]nm to 19.96[Formula: see text]nm. The optical bandgap decreases from 3.17[Formula: see text]eV to 3.08[Formula: see text]eV with the least value for Fe/ZnO NPs, according to UV–Vis spectral data, which also shows that the absorption edge changes to higher wavelengths (redshift). This research has produced nanoparticle samples of Ni/ZnO, Mg/ZnO, and Fe/ZnO that, when compared to the pure ZnO sample, show intriguing antibacterial activity.

Wide band gap tuning of Mg doped ZnO thin films for optoelectronic applications.

Zinc oxide (ZnO) thin films with magnesium (Mg) doping have demonstrated significant potential due to their wide band gap, which enables efficient absorption of ultraviolet (UV) radiation while maintaining transparency to visible light. Sol-gel spin coating methods were used to deposit Mg-doped ZnO thin films. The solution was made with methanol as the solvent, and the starting materials were magnesium acetate tetrahydrate and zinc acetate dihydrate. The integration of Mg content in deposited ZnO films was investigated for structural, morphological, and optical properties using an X-ray diffractometer (XRD), scanning electron microscope (SEM), energy dispersive X-ray analysis (EDAX), and UV-VIS spectrophotometer. Mg-doped ZnO films were produced on quartz substrates and post-annealed at 400°C. According to absorption coefficient calculations, the optical band gap of Mg-doped ZnO films is in the range of 5.4 eV which is ideal for a variety of applications in the field of optoelectronic devices.

Dipole Field-Driven Organic-Inorganic Heterojunction for Highly Sensitive Ultraviolet Photodetector.

Developing high-performance organic-inorganic ultraviolet (UV) photodetectors (PDs) has attracted considerable attention. However, this development has been hindered due to poor directional charge-transfer ratios in transport layers, excessive costs, and an ambiguous underlying mechanism. To tackle these challenges, we constructed a heterojunction of economic Mg-doped ZnO (MgZnO) nanorods and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) [PEDOT:PSS (P:P)] that utilizes dipole field-driven spontaneous polarization to enhance photogenerated charge kinetics. As a result, the proposed heterojunction has an improved noise equivalent power of 3.16 × 10-11 W Hz-1/2), a normalized detection rate (D*) of 8.96 × 109 jones, and external quantum efficiency comparable to other ZnO-based devices. Notably, the prepared PDs showed a photocurrent of 4.8 × 10-3 μA under a faint UV light having an intensity of 1 × 10-5 W cm-2, exceeding the performance of the most state-of-the-art ZnO-based UV sensors. The introduction of Mg into ZnO is responsible for the high performance, as it causes a lattice mismatch and distortion of the Mg-doped ZnO unit cell. It results in improved dipole movement and the creation of a dipole field, accelerating the directional electron-transfer process. Using a dipole field to manipulate the migration and transport of photogenerated carriers represents a promising approach for achieving outstanding performance in UV PDs.

Zinc Oxide and Magnesium-Doped Zinc Oxide Nanoparticles Ameliorate Murine Chronic Toxoplasmosis.

Toxoplasma gondii causes a global parasitic disease. Therapeutic options for eradicating toxoplasmosis are limited. In this study, ZnO and Mg-doped ZnO NPs were prepared, and their structural and morphological chrematistics were investigated. The XRD pattern revealed that Mg-doped ZnO NPs have weak crystallinity and a small crystallite size. FTIR and XPS analyses confirmed the integration of Mg ions into the ZnO framework, producing the high-purity Mg-doped ZnO nanocomposite. TEM micrographs determined the particle size of un-doped ZnO in the range of 29 nm, reduced to 23 nm with Mg2+ replacements. ZnO and Mg-doped ZnO NPs significantly decreased the number of brain cysts (p < 0.05) by 29.30% and 35.08%, respectively, compared to the infected untreated group. The administration of ZnO and Mg-doped ZnO NPs revealed a marked histopathological improvement in the brain, liver, and spleen. Furthermore, ZnO and Mg-doped ZnO NPs reduced P53 expression in the cerebral tissue while inducing CD31 expression, which indicated a protective effect against the infection-induced apoptosis and the restoration of balance between free radicals and antioxidant defense activity. In conclusion, the study proved these nanoparticles have antiparasitic, antiapoptotic, and angiogenetic effects. Being nontoxic compounds, these nanoparticles could be promising adjuvants in treating chronic toxoplasmosis.

Photocatalytic and Antimicrobial Properties of ZnO and Mg-Doped ZnO Nanoparticles Synthesized Using Lupinus albus Leaf Extract.

Dye effluents discharged from various industries contribute to environmental contamination, making their treatment highly necessary. Infectious diseases also pose a threat to public health worldwide. Nanomaterials have promising features and are potential candidates for overcoming the problems of drug resistance in microbes and environmental pollution. Therefore, this study aimed to synthesize zinc oxide (ZnO) and magnesium-doped zinc oxide (Mg-doped ZnO) nanoparticles (NPs) using the plant extract of Lupinus albus for applications in photocatalysis and antimicrobial activity. A sample of Lupinus albus leaves was collected from Motta, in the eastern Gojjam zone of Ethiopia. The leaves were air-dried and then ground into a powder. The powdered plant material was extracted using distilled water. The ZnO and Mg-doped ZnO NPs were synthesized using 0.1 M Zn(NO3)2·6H2O, 7.5% 0.1 M Mg(NO3)2.6H2O, and 10 mL of the leaf extract. The nanoparticles (NPs) were characterized using UV-vis, FT-IR, XRD, and SEM. The average crystallite sizes of ZnO and Mg-doped ZnO NPs were determined using the Debye-Scherrer formula and were found to be 28.1 and 34.4 nm, respectively. The antimicrobial activity of the synthesized NPs was evaluated against four bacterial strains (Escherichia coli, Bacillus cereus, Salmonella typhi, and Staphylococcus aureus) and one fungal strain (Candida albicans) by using the agar disk diffusion method. The Mg-doped ZnO NPs exhibited significant antimicrobial activity, with a maximum zone of inhibition measuring 24 and 22 mm against Escherichia coli and Salmonella typhi, respectively. The photocatalytic activity of ZnO and Mg-doped ZnO NPs was investigated by studying the degradation of methylene blue (MB) dye under sunlight irradiation for 120 min. The results showed that Mg-doped ZnO NPs exhibited higher photocatalytic activity (99.6%) than ZnO NPs (94.1%). In conclusion, the synthesized NPs could serve as viable alternatives for antimicrobial drugs and photocatalysts to mitigate the pollution of the environment caused by organic dyes.

Biofabrication of Mg-doped ZnO nanostructures for hemolysis and antibacterial properties.

The aim of this work was to synthesize 0.02 and 0.06Mg-doped ZnO nanoparticles (NPs) using the aqueous extract of Plectranthus barbatus leaf. The structural integrity of the hexagonal phase was emphasized by X-ray diffraction analysis. The average crystallite size (D) of 0.02 and 0.06Mg-doped ZnO NPs was found to be 23.83 and 26.95nm, respectively. The scanning electron microscope images revealed a surface morphology of irregular nano-shapes of about 83nm diameter with an elongated one-dimensional structure. The hemolysis activity demonstrated the safe nature of the synthesized materials at low doses. Antibacterial activity against S. aureus and E. coli, which assessed using the disc diffusion method, indicated that the prepared NPs could inhibit S. aureus but not E. coli. These findings suggest that the synthesized NPs could be explored for potential applications in biotechnology and medicine.

Passivating defects in ZnO electron transport layer for enhancing performance of red InP-based quantum dot light-emitting diodes

ZnO nanoparticles (NPs) are considered the most promising materials for electron transport layer (ETL) in quantum dot light-emitting diodes (QLEDs). Herein, we employed a synergistic strategy of Mg doping and ZnMgO shell coating to modify the defect states and energy levels of ZnO NPs. Mg doping mitigated the exciton luminescence quenching caused by charge transfer. A ZnMgO shell was also applied to coat the Mg-doped ZnO (ZMO) NPs to passivate surface oxygen defects further. Consequently, QLEDs utilizing ZMO@ZnMgO ETL demonstrate external quantum efficiency and maximum current efficiency of 9.0 % and 11.5 cd A−1. This work shows an effective defect passivation strategy to enhance the performance of red-emitting InP-based QLEDs.