Doped ZnO Research Articles

Physical Properties of Cu Doped ZnO Nanocrystiline Thin Films

Thin films of ZnO nano crystalline doped with different concentrations (0, 6, 9, 12, and 18 )wt. % of copper were deposited on a glass substrate via pulsed laser deposition method (PLD). The properties of ZnO: Cu thin-nanofilms have been studied by absorbing UV-VIS, X-ray diffraction (XRD) and atomic force microscopes (AFM). UV-VIS spectroscopy was used to determine the type and value of the optical energy gap, while X-ray diffraction was used to examine the structure and determine the size of the crystals. Atomic force microscopes were used to study the surface formation of precipitated materials. The UV-VIS spectroscopy was used to determine the type and value of the optical energy gap.

Physical Properties of Pure Gold Nanoparticles and Gold Doped ZnO Nanoparticles Using Laser Ablation in Liquid For Sensor Applications

In this paper, the effect of using laser ablation of pure gold targets to obtain gold Nano rods and for pure zinc targets to obtain zinc oxide nanoparticles was studied separately in ethanol using an Nd:YAG laser tattoo removal (nanosecond pulses) and then mixing the resulting mixtures to obtain gold dopant with zinc oxide. Transmission electron microscopy (TEM), (XRD) X-Ray Diffraction and the optical properties were used to characterize the pure gold Nano rods, ZnO nanoparticles, and Au doped ZnO nanoparticles. Based on XRD and TEM, the results revealed the properties of the produced gold Nano roads. The obtained results indicated that the gold Nano rods produced by the 1064nm laser have superior optical, structural, and morphological properties and can be used in different sensors.

Highly Efficient Visible Light Active Doped ZnO Photocatalysts for the Treatment of Wastewater Contaminated with Dyes and Pathogens of Emerging Concern.

Water is obligatory for sustaining life on Earth. About 71% of the Earth’s surface is covered in water. However, only one percent of the total water is drinkable. The presence of contaminants in wastewater, surface water, groundwater, and drinking water is a serious threat to human and environmental health. Their toxic effects and resistance towards conventional water treatment methods have compelled the scientific community to search for an environmentally friendly method that could efficiently degrade toxic contaminants. In this regard, visible light active photocatalysts have proved to be efficient in eliminating a wide variety of water toxins. A plethora of research activities have been carried out and significant amounts of funds are spent on the monitoring and removal of water contaminants, but relatively little attention has been paid to the degradation of persistent water pollutants. In this regard, nanoparticles of doped ZnO are preferred options owing to their low recombination rate and excellent photocatalytic and antimicrobial activity under irradiation of solar light. The current article presents the roles of these nanomaterials for wastewater treatment from pollutants of emerging concern.

Preparation and Characterization of Cu and Al Doped ZnO Thin Films for Solar Cell Applications

The Al- and Cu-doped ZnO nanostructured films in this study were deposited using a sputtering technique. Investigations based on X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, Hall effect measurements, and optical transmission spectroscopy was performed to analyze the structural, electrical, and optical characteristics of the prepared Al–ZnO and Cu–ZnO nanostructured films. The analyses show that doping results in enhanced conductivity as well as improved mobility in Al–ZnO and Cu–ZnO films in comparison to pure ZnO films. The Al- and Cu-doped ZnO films exhibited low resistivity (2.9 × 10−4 Ω cm for Al–ZnO and 1.7 × 10−4 Ω cm for Cu–ZnO) along with an average transmittance of around 80% in the visible spectrum. Moreover, the optical bandgaps of undoped ZnO, Al–ZnO, and Cu–ZnO nanostructures were observed as 3.3, 3.28, and 3.24 eV, respectively. Finally, solar cells were assembled by employing ZnO nanostructured thin films as photoelectrodes, resulting in efficiencies of 0.492% and 0.559% for Al–ZnO- and Cu–ZnO-based solar cells, respectively.

Structural, optical and electrical properties of undoped and doped (Al, Al + Mn) ZnO nanoparticles synthesised by green combustion method using terminalia catappa seed extract

This paper presents the synthesis of undoped and doped (Al, Al + Mn) ZnO nanoparticles by green combustion method using Terminalia Catappa seed extract as a novel fuel and Zinc nitrate as a precursor, Aluminum nitrate and Magnesium chloride was used as dopant. Synthesized undoped and doped ZnO nanoparticles were characterized by XRD, FESEM, FTIR, UV-visible spectroscopy and impedance spectroscopy. The XRD study of undoped and doped (Al, Al + Mn) ZnO nanoparticles exhibits hexagonal wurtzite structure with high crystallinity. The crystallite size increases from 37.5 nm to 39 nm for Al doping and decreased to 30.5 nm for Al + Mn doped ZnO nanoparticles. Mean grain size of undoped ZnO nanoparticles was found to be 32.5 nm. For Al doped ZnO nanoparticles mean grain size increases (42.9 nm) and then decreases (21.25 nm) for Al + Mn doped ZnO nanoparticles. FTIR studies confirms the formation of Zn-O bond at 462, 455 and 439 cm−1 for both undoped and doped ZnO nanoparticles. The optical band gap was found to be 3.25, 3.2 and 2.54 eV for undoped and doped (Al , Al + Mn) ZnO nanoparticles respectively. The dielectric properties and conductivity studies were carried for undoped and doped (Al, Al + Mn) ZnO nanoparticles at various fixed temperatures (50 to 350 °C) by varying frequency from 10 Hz to 8 MHz. Dielectric constant increases with rise in temperature and, dielectric constant decreases with rise in frequency and remains constant at higher frequency. At lower frequencies AC conductivity was constant and increases as the frequency increases. Grain and grain boundary resistance for the synthesised ZnO nanoparticles were studied by complex impedance analysis and result exhibits a decrease in grain resistance with rise in temperature. The ZnO nanoparticles doped with Al shows improved microstructural properties, decreased optical band gap and activation energy. Hence these nanoparticles are suitable material for sensors and optoelectronics applications.

Synthesis, Structural and Optical Properties of Cu Doped Zno and Cuo-Zno Composites Nanoparticles

Synthesis, Structural and Optical Properties of Cu Doped Zno and Cuo-Zno Composites Nanoparticles

Enhanced dielectric properties and chemical bond characteristics of ZnNb2O6 ceramics due to zinc oxide doping

Regarding advanced 5G mobile communication, microwave dielectric ceramics are considered as the most potential materials to develop new-generation base station resonators. Herein, ZnNb 2 O 6 ceramics with ε r of approximately 24 have been prepared using the solid-state reaction method, with tailored extra ZnO of x mol% (x = 1, 2 and 3). We have for the first time applied the P-V-L chemical bond theory to investigate ZnNb 2 O 6 ceramics with ZnO doping, by exploring the relationship of dielectric properties and chemical bond characteristics. Particularly, the Raman spectra demonstrates that the full width at half maximum of υ 1 (A g ) vibration mode can exhibit significant correlation with the quality factor ( Q × f ). To further support the experimental study, we have also conducted the first-principle calculation of electron density difference via CASTEP package, which further confirms the change of temperature coefficient of resonance frequency ( τ f ). Our newly designed ZnNb 2 O 6 ceramics doped with 1 mol% ZnO exhibit excellent dielectric properties, i.e., ε r = 23.74, Q × f = 102,824 GHz and τ f = −55.38 ppm/°C, which demonstrates great potential to construct miniaturized 5G base station with advanced ceramic dielectrics.

Application of silicon nanoparticles extracted from the Padma river sand of Bangladesh as dopant in metal oxide semiconducting thin films

Fabrication of silicon nanoparticles (Si-NPs) from the Padma river sand of Bangladesh by a low-temperature, low-cost, and zero-CO2 emitting process and its application as a dopant in CuO and ZnO have been presented in this article with a motivation to see the influence of locally fabricated Si-NPs on the optoelectronic properties of CuO and ZnO thin films. The sand (SiO2) was reduced using a modified aluminothermic reaction, and leaching with hydrochloric acid (HCL) was used to purify the reaction product to extract > 98% pure Si. After cleaning and drying, the obtained Si powder was ultrasonicated for crushing them into tiny particles of 60–180 nm. The ultrasonicated silicon was further treated with a solution of hydrofluoric acid (HF) and 2-propanol for the etching of the native oxide and passivating the dangling bond with hydrogen (H). Thereafter, highly promising photoactive materials CuO and ZnO were doped with the extracted Si-NPs. Finally, Si-NPs doped CuO and ZnO thin films were deposited on a cleaned glass substrate by spin-coating. X-Ray Diffraction (XRD) confirmed the amorphous nature of Si particles. Dynamic Light Scattering (DLS) demonstrates the size distribution of Si-NPs of ~120 nm for 180 minutes of sonication time. DLS results refer that the higher sonication time offers a lower particle size of Si with controlled rate. The addition of Si-NPs nanoparticles tailors the energy band alignment at the metal oxide/NP interface which provides efficient charge carrier transport and enhanced optical absorption (~20%) as revealed by UV-Vis Spectroscopy. Experimental results indicate that the extracted Si-NPs can be efficiently used in thin-film based optical and electronic devices.

Oxygen sensing with individual ZnO:Sb micro-wires: effects of temperature and light exposure on the sensitivity and stability.

Nanostructured ZnO has been widely investigated as a gas sensing material. Antimony is an important dopant for ZnO that catalyses its surface reactivity and thus strengthens its gas sensing capability. However, there are not enough studies on the gas sensing of antimony-doped ZnO single wires. We fabricated and characterized ZnO/ZnO:Sb core–shell micro-wires and demonstrated that individual wires are sensitive to oxygen gas flow. Temperature and light illumination strongly affect the oxygen gas sensitivity and stability of these individual wires. It was found that these micro- and nano-wire oxygen sensors at 200°C give the highest response to oxygen, yet a vanishingly small effect of light and temperature variations. The underlying physics and the interplay between these effects are discussed in terms of surface-adsorbed oxygen, oxygen vacancies and hydrogen doping.

Effective role of Rb doping in controlling the crystallization, crystal imperfections, and microstructural and morphological features of ZnO-NPs synthesized by the sol–gel approach

This article is allocated to synthesizing pure ZnO and Rb-doped ZnO nanoparticles, RbxZn1−xO-NPs via the sol–gel technique and then studying the effect of Rb doping ZnO on the crystal structure, microstructure parameters and morphology of the host lattice.

Optical and photoluminescence studies of precursor stabilized gallium zinc oxide thin films

Precursor stabilized Gallium doped ZnO thin films were grown using spray pyrolysis on glass substrates. UV–vis spectrophotometry and an X-ray diffractometer were used to characterise the GZO thin films. Gallium is doped with a concentration ranging from 1 at% to 4 at% and its effects on structural and optical features were studied. XRD studies found the thin films to be polycrystalline with a hexagonal wurtzite structure. In the visible range of wavelength (400–800 nm), all GZO films exhibit average transmittance above 90%, with a pronounced absorption edge in the UV area. The PL emission spectra show the Near-band-edge emissions at about 389 nm and strong deep-level emissions from oxygen defect states at about 545 nm are observed in all the films. With increase in concentration of Ga, the intensity of these two bands decreased.

High Efficiency Adsorptive Removal of Phenol Using Ag Doped Zno Nanoparticles

High Efficiency Adsorptive Removal of Phenol Using Ag Doped Zno Nanoparticles

Violet Photoluminescence and Magnetic Characteristics of Hydrothermally Grown Co2+, Ni2+ and Cu2+ Doped Zno Nanostructures

Violet Photoluminescence and Magnetic Characteristics of Hydrothermally Grown Co2+, Ni2+ and Cu2+ Doped Zno Nanostructures

Understanding of Mobility Limiting Factors in Solution Grown Al Doped ZnO Thin Film and its Low Temperature Remedy

Understanding of Mobility Limiting Factors in Solution Grown Al Doped ZnO Thin Film and its Low Temperature Remedy

Plasma assisted synthesis of cobalt-doped ZnO nanoparticles in liquid

Cobalt-doped ZnO nanoparticles were synthesized by electrical discharge treatment of a mixture of metallic zinc and cobalt micropowders (with Co atomic concentration of 10%) in distilled water. The results of the characterization of inner structure, phase composition and morphology of the prepared samples performed by means of TEM, XRD, FTIR and UV–Vis spectroscopy proved the formation of near-spherical doped ZnO:Co nanocrystals under the found optimized experimental conditions. The band gap of the Co-doped ZnO nanoparticles was estimated to be 2.88 eV in comparison to the pure ZnO – 3.28 eV. The broad luminescence band associated with the formation of defect levels in Co-doped ZnO was observed the range from 450 nm to 750 nm. The prepared Co-doped ZnO nanocrystals exhibited ferromagnetic behavior at room temperature that can be useful for their application in spintronics.

Electrochemical, Optical and Morphological Characterizations of Cu Doped ZnO Nanostructure Thin Films Prepared by Spin Coating Method

From nanotechnology point of view where conductivity is crucial, although it is essential to determine the electrochemical properties Cu doped ZnO nanostructure thin films produced by spin coating, there are rare studies in the literature. Therefore, in this study, the aim was to examine thouroughly the electrochemical properties of nanostructure thin films which were grown on glass substrates by using a facile and cost-effective spin coating method. The effects of the dopant on the morphological, optical and electrochemical properties of ZnO nanostructure thin films doped with Cu at different concentrations (0-50%) were investigated by SEM, XRF, FTIR, UV-vis, mechanical profilometer, and cyclic voltametry. The absorption spectra of the samples revealed that the energy band gap value decreased by the incereasing of Cu doping concentration. SEM images depicted that more spherical and homogeneous nanostructures formed with the doping of Cu. Electrochemical results showed that increasing the Cu doping ratio in ZnO nanoparticles results in higher electron transfer indicating that the conductivity of ZnO nanostructured thin films increases with Cu doping. It can be concluded that it is possible to produce more homogeneous, wider spectrum absorption capable and more conductive nanostructure thin films by a simple and inexpensive method. It is envisaged that the thin films obtained are promising for a wide range of nanotechnology applications.

Synthesis of Boron Doped ZnO Nanoparticles and Experimental/Theoretical Investigation of Structural, Morphological, Optical Properties

Bu çalışmada, sprey piroliz yöntemi ile farklı molar oranlarda (%0, 0.2, 0.5, 1, ve 2) bor katkılı ZnO nanoparçacıkları elde edilmiştir. Katkısız ve katkılı ZnO nanoparçacıklarının karakterizasyonu, X-ışını kırınımı (XRD) tekniği, yüzey morfolojisi Taramalı Elektron Mikroskobu (SEM) ve optik özellikler ultraviyole-görünür bölge spektrumu ölçülerek yapılmıştır. XRD analiz sonuçları, wurtzite kristal yapıda ZnO nanoparçacıklarının elde edildiğini göstermektedir. Bant aralığı enerjisi (Eg) her bir numune için 2.98 –3.15 eV aralığında bulunmuş ve katkı maddelerinin bant enerjisini artırdığı gözlemlenmiştir. Ayrıca 10 metal ve oksijen atomundan oluşan küme yapıları yarı deneysel/pm6 yöntemi ile optimize edilmiş, kuramsal band boşluğu enerjisi hesaplanmıştır.

Enhanced light absorption and charge separation of In‐doped ZnO nanorod arrays for photoelectrochemical water‐splitting application

Elemental doping promises an efficient strategy to modify and optimize the performance of metal oxide photoanodes. Herein, we introduce a simple hydrothermal method to fabricate In-doped ZnO thin films on the fluorine-doped tin oxide (FTO) to use as a photoanode for water splitting application. The effects of In-doping on the structural, optical, morphological, and electrical properties of ZnO nanorods were studied. PEC results indicate that the 5% In doped ZnO photoanode determined an outstanding photocurrent density reached 0.42 mA/cm2 at 0.64 VAg/AgCl, which is four times higher than the undoped ZnO sample (0.1 mA/cm2). Furthermore, Ultraviolet-visible spectroscopy (UV-Vis) and photoluminescence spectroscopy (PL) studies showed a red-shift in the band edge of doped samples compared to the pure samples, which indicate that the light absorption is enhanced. We find that the optimal doping of In (5%) leads to smaller charge transfer resistance and higher electron transfer rate as confirmed from EIS analysis. Therefore, fabricated In-doped ZnO could be a favorable and potential photoelectrode for light-harvesting and water splitting application.

Aluminum Doped ZnO Nanorods for Enhanced Phenylhydrazine Chemical Sensor Applications

The fabrication and characterization of nanorod-shaped Al-doped ZnO nanostructures are described in this paper. The hexagonal wurtzite phase of ZnO was confirmed by XRD investigation, with efficient doping of Aluminum ions in the ZnO crystal. The length and diameter of the high density produced doped ZnO nanorods were shown to be heterogeneous using FESEM analysis. EDS, FTIR, and Raman spectroscopy examinations validated purity, composition, and vibrational characteristics. Even at very low analyte concentrations, the constructed Al-doped ZnO nanorods modified silver electrode (AgE) displayed exceptional electron mediating characteristics towards phenylhydrazine. The sensitivity, linear dynamic concentration range (LDR) and limit of detection (LOD) were found to be 64.77 μAmM−1cm−2, 0.313–2.5 mM, and 0.313 mM, respectively. As a result of the research described, Al-doped ZnO nanorods appear to be promising candidates for building efficient and repeatable electrochemical sensors in the future.

Thermal behavior, structure, crystallization and solubility of the melt-derived SiO2–P2O5–Na2O–F-MO (M = Ca, Sr, Zn) glasses

In this work, phospho-silicate glasses with SiO2–P2O5–Na2O–F-MO (M = Ca, Sr, Zn) composition were prepared by using the conventional melt quenching technology. Structural, physical, and chemical property tests were used to analyze the effects of different SrO and ZnO content on the structure and properties of the glasses. The results showed that the glass stability varied nonlinearly as CaO was replaced by SrO, which was mainly related to the different positions of Sr2+ and Ca2+ ions breaking the network connection in the network structure, and the substitution of ZnO for CaO led to a continuous decrease in the stability of the glasses. The immersion experiment showed that SrO doping was more feasible than ZnO doping to improve the biological activity of the glasses, and the doping of ZnO promoted the dissolution of ions in the glasses. The obtained results indicated that the glass samples prepared in this paper have potential biological activity, which has potential applications in dental treatment.