Zinc Atoms Research Articles

In-situ physical/chemical cross-linked hydrogel electrolyte achieving ultra-stable zinc anode-electrolyte interface towards dendrite-free zinc ion battery

Hydrogen evolution reaction (HER), zinc corrosion, and dendrites growth on zinc metal anode are the major issues limiting the practical applications of zinc-ion batteries. Herein, an in-situ physical/chemical cross-linked hydrogel electrolyte (carrageenan/polyacrylamide/ZnSO4, denoted as CPZ) has been developed to stabilize the zinc anode-electrolyte interface, which can eliminate side reactions and prevent dendrites growth. The in-situ CPZ hydrogel electrolyte improves the reversibility of zinc anode due to eliminating side reactions caused by active water molecules. Furthermore, the electrostatic interaction between the SO4−· groups in CPZ and Zn2+ can encourage the preferential deposition of zinc atoms on (002) crystal plane, which achieve dendrite-free and homogeneous zinc deposition. The in-situ hydrogel electrolyte offers a streamlined approach to battery manufacturing by allowing for direct integration into the battery. Subsequently, the Zn//Zn half battery with CPZ hydrogel electrolyte can enable an ultra-long cycle over 5500 h at a current density of 0.5 mA cm−2, and the Zn//Cu half battery reach an average coulombic efficiency of 99.37%. The Zn//V2O5-GO full battery with CPZ hydrogel electrolyte demonstrates 94.5% of capacity retention after 2100 cycles. This study is expected to open new thought for the development of commercial hydrogel electrolytes for low-cost and long-life zinc-ion batteries.

Hydrindacene‐Based Zinc Aryl Thiolate and Aryl Selenolate Zn(EMSFluind)2 (E=S, Se)

AbstractThe bulky aryl thiol, MSFluindSH (1S), and aryl selenol, MSFluindSeH (1Se), possessing a tetramethyl‐s‐hydrindacen‐4’‐yl‐(Rind)‐based substituent containing two fluorenyl groups in 9 and 9’‐positions, were prepared (MSFluind=dispiro[fluorene‐9,3’‐(1’,1’,7’,7’‐tetramethyl‐s‐hydrindacene‐4’‐yl)‐5’,9’’‐fluorene]). The reaction of 1S and 1Se with Et2Zn provided a monomeric zinc aryl thiolate, Zn(SMSFluind)2 (2S), and zinc aryl selenolate, Zn(SeMSFluind)2 (2Se), with essentially two‐coordinate zinc atoms.

Engineering the Activity and Stability of the Zn-MOF Catalyst via the Interaction of Doped Zr with Zn.

Metallic atoms within metal-organic framework (MOF) materials exhibit a distinctive and adaptable coordination structure. The three-dimensional (3D) pore configuration of MOFs enables the complete exposure of metal active sites, rendering them prevalent in various catalytic reactions. In this study, zinc (Zn) atoms within Zn-based MOF materials, characterized by an abundance of valence electrons, are utilized for the transesterification of dimethyl carbonate (DMC). Additionally, the introduction of zirconium (Zr) effectively addresses the susceptibility of the MOFs' crystal structure to dissolution in organic solvents. The formulated catalyst, Zn-10%Zr-MOF(300), demonstrates remarkable catalytic performance with 91.5% DMC selectivity, 61.9% propylene carbonate (PC) conversion, and 56.6% DMC yield. Impressively, the catalyst maintains its high performance over five cycles. Results indicate that Zr interacts with Zn, forming new coordination bonds and enhancing the catalyst crystal structure stability. Moreover, electron transfer intensifies the alkalinity of the active Zn atoms, enhancing the overall catalyst performance. This research informs the development of transesterification heterogeneous catalysts and broadens the application scope of MOF catalysts.

Zn-Ti oxo cluster photoresists for EUV Lithography: Cluster structure and lithographic performance

Low reflectivity of multilayer mirror–induced low efficiency of existing extreme ultraviolet lithography (EUVL) has triggered the search for photoresists with heightened sensitivity. For this purpose, considerable research has focused on elements with high extreme ultraviolet (EUV) absorption, leading to considerable advancements. Solubility alteration, often resulting from ligand variations after exposure, is influenced by the cluster structure, markedly impacting lithography sensitivity. Herein, three Ti-based metal clusters, Ti6O4(OEt)8(OMc)8 (T-2), Zn2Ti4O4(OiPr)2(OMc)10 (TZ-1), and Zn4Ti2O2(OAc)2(OBu)2(OMc)10 (TZ-2), are designed and synthesized to elucidate the effects of the structure on lithography. These mixed metal–oxo clusters derived from Ti6O4(OR)8(OOCR)8 and stabilized by identical ligands exhibit structural diversity. The increase in the number of zinc atoms results in marked alterations in the oxo core, thereby triggering alterations in ligand coordination modes. These variations confer metal clusters with different solubility and lithographic properties. Analysis of the photochemical reaction mechanism and theoretical calculations reveal a reactive tridentate ligand coordination mode that considerably improves lithography sensitivity. Therefore, changing the ligand coordination mode by designing a mixed metal–oxo core holds promise for discovering new photoresists for EUV lithography.

Ab Initio Computation of Auger Decay in Heavy Metals: Zinc about It.

We report the first coupled-cluster study of Auger decay in heavy metals. The zinc atom is used as a case study due to its relevance to the Auger emission properties of the 67Ga radionuclide. Coupled-cluster theory combined with complex basis functions is used to describe the transient nature of the core-ionized zinc atom. We also introduce second-order Møller-Plesset perturbation theory as an alternative method for computing partial Auger decay widths. Scalar-relativistic effects are included in our approach for computing Auger electron energies by means of the spin-free exact two-component one-electron Hamiltonian, while spin-orbit coupling is treated by means of perturbation theory. We center our attention on the K-edge Auger decay of zinc dividing the spectrum into three parts (K-LL, K-LM, and K-MM) according to the shells involved in the decay. The computed Auger spectra are in good agreement with experimental results. The most intense peak is found at an Auger electron energy of 7432 eV, which corresponds to a 1D2 final state arising from K-L2L3 transitions. Our results highlight the importance of relativistic effects for describing Auger decay in heavier nuclei. Furthermore, the effect of a first solvation shell is studied by modeling Auger decay in the hexaaqua-zinc(II) complex. We find that K-edge Auger decay is slightly enhanced by the presence of the water molecules as compared to the bare atom.

Morphological, structural and electronic properties of zinc oxide nano structures deposited on ZnO substrate layer – A theoretical perspective

The work investigates the deposition of zinc and oxygen atoms on a Zinc terminated ZnO substrate, maintaining their stoichiometric ratio (O:Zn) at 0.8, under varying incident energies (0.5 eV and 5 eV) and temperatures (300 K and 700 K) using the ReaxFF potential in Molecular Dynamics (MD) simulation. The study explores the impact of deposition conditions on growth mechanisms, film morphology, and structural parameters such as Radial Distribution Function (RDF) and Coordination Number (CN). RDF analysis highlights disordered atomic arrangements and diverse bonding configurations within the film, with CN showing deviations from perfect crystalline ZnO, indicating non-uniform, non-crystalline, and nano behaviour. Post-heating the films to temperatures approaching the ZnO melting point results in enhanced crystallinity, as evidenced by distinct, dominant, and multiple RDF peaks. Density Functional Theory (DFT) approach of the deposited structures elucidates the formation of ZnO nanoclusters-(ZnO)3 and (ZnO)4 and investigates their electronic structure properties. DFT analysis of the post-heated films reveals the formation of ZnO monomers (ZnO), indicating an approaching crystalline behaviour, yet the films exhibit non-epitaxial and non-uniform characteristics. DFT calculations were instrumental in validating the observed structural behaviours in the deposited films. The study underscores the significance of stoichiometric ratio in film deposition and demonstrates the temperature-dependent evolution of structural properties towards crystallinity, shedding light on the intricate dynamics of ZnO film growth offering tailored control over film properties for enhanced performance in practical applications such as optoelectronics and gas sensing.

Formation of Binary Compounds of Impurity Atoms of Sulfur and Zinc in Silicon

The paper presents the information on thermodynamic conditions and describes process stages required in order to form binary zinc-and-sulfur (ZnS) elementary cells in single-crystalline silicon while doping it with impurity atoms of group II and VI elements, i.e., zinc and sulfur, respectively. The thermodynamic conditions that ensure shaping of such elementary cells in silicon have been established. It has also been revealed that before binary compound (consisting of zinc and sulfur atoms) nanoclusters, those chemical elements may have been present in the silicon matrix in the form of separately located atoms or various naturаl compounds. It is supposed that it might be possible to engineer previously-unknown silicon-based materials with unique fundamental properties by applying the technique of assembling elementary cells and binary compounds of the ZnS type with pre-set concentrations. Using a scanning tunneling microscope, it was possible to determine the elemental composition of binary compounds that were formed in the matrix and on the surface of a silicon sample. An analysis of the results of the above experiments showed that binary compounds of the ZnS type are possibly formed in the Si crystalline sample characterized by new electrophysical parameters.

Symmetry Evolution Induced 2D Pt Single Atom Catalyst with High Density for Alkaline Hydrogen Oxidation.

The performance of single-atom catalysts is greatly influenced by the chemical environment surrounding the central atom. Here, a salt-assisted method is employed to transform the tetrahedral coordination structure of zeolitic imidazolate frameworks - 8 (ZIF-8)into a planar square coordination structure without altering the ligands. During the subsequent carbonization process, concurrent with the evaporation of zinc atoms, the structure of the nitrogen and carbon carriers (NC carriers) undergoes a transition from five-membered rings to six-membered rings to preserve the 2D structure. This transition results in the generation of additional defect sites on the 2D-NC substrates. Hence, the Pt single-atom catalysts with planar square coordination symmetries can be precisely prepared via electrodeposition (denoted as 2D-Pt SAC). The Pt loading of 2D-Pt SAC is 0.49 ± 0.03 µg cm-2, higher than that of 3D-Pt SAC (0.37 ± 0.04 µg cm-2). In the context of the hydrogen oxidation reaction electrocatalysis, under an overpotential of 50 mV, these single-atom catalysts with 2D coordination exhibit mass activities of 2396 A gPt -1 (32 times higher than commercial Pt/C catalyst, 2 times higher than 3D-PtNC).

Use of <i>Hermetia illucens</i> hermicompost in the technology of growing legume microgreens

Relevance. The work describes the prospect of using black soldier fly zoohumus as an organic fertilizer to activate the growth of microgreens of non-traditional legume species, including small-seeded ones, and the prospects of reducing the dose of mineral fertilizers.Methods. An experiment was carried out with a comparative study of changes in the morphometric and chemical parameters of plant growth at the full recommended dose of mineral fertilizers, and at 25% of their use, but with the addition of 1% liquid extract of zoohumus, also enriched with essential elements. The duration of the experiment was 21 days. The plants were grown in a closed grow tent, with intensive light culture and control of the internal microclimate of the working area.Results. Among the six studied non-traditional legume species grown for microgreens, the most responsive to combined treatment with an organomineral complex was Onobrychis viciifolia. Trifolium rubens showed the worst result in terms of biomass. Analysis of changes in the profile distribution of essential elements in the resulting green biomass, carried out using inductively coupled plasma atomic emission spectroscopy (ICP-AES), revealed iron and zinc ions as potential targets associated with yield shortfalls in juvenile shoots. Since in global food systems these microelements are the most common nutrients noted for the manifestation of “hidden hunger”, especially among children under 5 years of age and women of childbearing age, when creating a nutritional biocomposition based on black soldier fly zoohumus for growing non-traditional types of legumes, further the emphasis should be on them. No significant differences were found in the number of macroelements.Results. The results of the study confirmed the high efficiency of using humic fertilizers in conditions of low soil fertility and revealed the selective sensitivity of vegetable crops to humic preparations of various origins.

Ultrasound-assisted extractive-catalytic removal of micro-organic pollutants in liquid hydrocarbon fuels using highly active ZnO nanoparticles supported zinc-substituted phosphotungstate

To produce ultra-low sulfur diesel (ULSD), it is necessary to remove compounds such as 2-methylthiophene and 3-methylthiophene that cannot be isolated by conventional industrial methods. This paper presents, a phosphotungstate catalyst improved with zinc atoms placed on the surface of super active zinc oxide nanoparticles and is able to switch between two phases using a hydrophobic ionic liquid (transfer agent). Here, is a description of the synthesis of the α-keggin type hybrid nanocatalyst and its application for the removal of 2- methylthiophene and 3-methylthiophene. The nanocatalyst was subjected to various characterization techniques, including Fourier Transform Infrared Spectrometer (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) Surface Area Analysis, Barrett-Joyner-Halenda (BJH) pore size and volume analysis and Energy-dispersive X-ray analysis(EDAX). The optimized conditions for the ultrasound-assisted extractive-catalytic oxidative desulfurization (UA-ECODS) process were determined using a statistical design, specifically the Box-Behnken design (BBD), which was proposed as a plan for designing experiments and studying the behavior of the parameters. The optimal conditions, which encompass four parameters, namely ultrasonic time, reactor temperature, amount of nanocatalyst, and oxidant concentration, are archived as 14.43 min, 40.52 °C, 86.27 mg catalyst, and 24 % H2O2 Respectively. The results indicated that the removal efficiency was higher for 2- methylthiophene than 3-methylthiophene. The paper concludes that the UA-ECODS method utilizing the synthesized nanocatalyst is a promising and effective approach for desulfurizing of liquid hydrocarbon fuels.

Size effects and electronic properties of zinc-doped boron clusters Zn (n = 1-15).

To gain a deeper understanding of zinc-doped boron clusters, theoretical calculations were performed to investigate the size effects and electronic properties of zinc-doped boron clusters. The study of the electronic properties, spectral characteristics, and geometric structures of Zn (n = 1-15) is of great significance in the fields of semiconductor materials science, material detection, and improving catalytic efficiency. The results indicate that Zn (n = 1-15) clusters predominantly exhibit planar or quasi-planar structures, with the Zn atom positioned in the outer regions of the framework. The second stable structure of Zn is a three-dimensional configuration, indicating that the structures of zinc-doped boron clusters begin to convert from the planar or quasi-planar structures to the 3D configurations. The second low-energy structure of Zn is a novel configuration. Relative stability analyses show that the Zn has better chemical stability than other clusters with a HOMO-LUMO gap of 2.79 eV. Electric charge analysis shows that part electrons on zinc atoms are transferred to boron atoms, and electrons prefer to cluster near the framework. According to the electron localization function, it gets harder to localize electrons as the equivalent face value drops, and it's challenging to see covalent bond formation between zinc and boron atoms. The spectrograms of Zn (n = 1-15) exhibit distinct properties and notable spectral features, which can be used as a theoretical basis for the identification and confirmation of boron clusters doped with single-atom transition metals. The calculations were performed using the ABCluster global search technique combined with density functional theory (DFT) methods. The selected low-energy structures were subjected to geometric optimization and frequency calculations at the PBE0/6-311 G(d) level to ensure structural stability and eliminate any imaginary frequencies. To acquire more precise relative energies, we performed single-point energies calculations for the low-lying isomers of Zn (n = 1-15) at the CCSD(T)/6-311 G(d)//PBE0/6-311 G(d) level of theory. All calculations were performed using Gaussian 09 software. To facilitate analysis, we utilized software tools such as Multiwfn, and VMD.

Two-point connected complex of zinc aminoporphyrin with histidine protected at α-amino and imidazolyl-π nitrogen atoms

Abstract Zinc porphyrins possessing an (N,N-dialkylamino)methyl group at the peripheral position were prepared from β-octaethylporphyrin. The synthetic zinc aminoporphyrins were complexed with an Nα,Nim(τ)-protected histidine through the coordination of the histidyl imidazolyl-τ nitrogen atom with the central zinc atom and the concomitant hydrogen bonding of the histidyl carboxy group with the peripheral amino group. The 1:1 complexation in the chloroform was dependent on the size of the alkyl groups on the peripheral aminomethyl nitrogen atom. The diethyl substitute complexed more strongly than the dimethyl and dipropyl counterparts. The complexation of zinc (diethylamino)methyl-porphyrin with an Nα,Nim(π)-protected histidine was 260-fold stronger than that with the above Nα,Nim(τ)-protected histidine to exhibit the association constant of 2.6 × 106 M−1. The significant enhancement was ascribable to the less sterically demanding and more coordinating Nim(τ)-atom compared with the Nim(π)-atom. The achiral zinc aminoporphyrin was complexed with the chiral Nα,Nim(π)-protected histidine to give a circular dichroism active species in a visible Soret region.

Boron nitride doped with transition metals for carbon monoxide detection: a promising nanosensor for air cleaning

PurposeThis study aims to investigate the potential of the decorated boron nitride nanocage (BNNc) with transition metals for capturing carbon monoxide (CO) as a toxic gas in the air.Design/methodology/approachBNNc was modeled in the presence of doping atoms of titanium (Ti), vanadium (V), chromium (Cr), cobalt (Co), copper (Cu) and zinc (Zn) which can increase the gas sensing ability of BNNc. In this research, the calculations have been accomplished by CAM–B3LYP–D3/EPR–3, LANL2DZ level of theory. The trapping of CO molecules by (Ti, V, Cr, Co, Cu, Zn)–BNNc has been successfully incorporated because of binding formation consisting of C → Ti, C → V, C → Cr, C → Co, C → Cu, C → Zn.FindingsNuclear quadrupole resonance data has indicated that Cu-doped or Co-doped on pristine BNNc has high fluctuations between Bader charge versus electric potential, which can be appropriate options with the highest tendency for electron accepting in the gas adsorption process. Furthermore, nuclear magnetic resonance spectroscopy has explored that the yield of electron accepting for doping atoms on the (Ti, V, Cr, Co, Cu, Zn)–BNNc in CO molecules adsorption can be ordered as follows: Cu > Co >> Cr > Zn ˜ V> Ti that exhibits the strength of the covalent bond between Ti, V, Cr, Co, Cu, Zn and CO. In fact, the adsorption of CO gas molecules can introduce spin polarization on the (Ti, V, Cr, Co, Cu, Zn)–BNNc which specifies that these surfaces may be used as magnetic-scavenging surface as a gas detector. Gibbs free energy based on IR spectroscopy for adsorption of CO molecules adsorption on the (Ti, V, Cr, Co, Cu, Zn)–BNNc have exhibited that for a given number of carbon donor sites in CO, the stabilities of complexes owing to doping atoms of Ti, V, Cr, Co, Cu, Zn can be considered as: CO →Cu–BNNc >> CO → Co–BNNc > CO → Cr–BNNc > CO → V–BNNc > CO → Zn–BNNc > CO → Ti–BNNc.Originality/valueThis study by using materials modeling approaches and decorating of nanomaterials with transition metals is supposed to introduce new efficient nanosensors in applications for selective sensing of carbon monoxide.

Zinc caproate: Ecofriendly synthesis, structural characterization, and antibacterial action

Disease-causing microorganisms such as Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are among the primary contributors to morbidity and mortality of diarrhea in humans. Considering the challenges associated with antibiotic use, including antimicrobial resistance, this study aimed to develop a novel zinc-based agent for bacterial inactivation. To this end, zinc caproate (ZnCA) was synthesized using caproic acid (CA) and zinc oxide (ZnO) in anhydrous ethanol via the solvothermal method. Structural characterization techniques, including Fourier-transform infrared spectroscopy, single crystal X-ray diffraction analysis, and nuclear magnetic resonance spectroscopy, revealed the bidentate bridging coordination of zinc atoms with CA. The resulting two-dimensional ZnCA network was found to be composed of a distinct lamellar pattern, without any evident inter-layer interactions. Powder X-ray diffraction analysis, elemental analysis, and melting point analysis confirmed that ZnCA had an average particle size of 1.320 µm, a melting point of 147.2 °C, and a purity exceeding 98 %. Remarkably, ZnCA demonstrated potent antibacterial activity against E. coli and S. aureus, which exceeded the antibacterial efficacy of ZnO. ZnCA exerted its antibacterial effects by inhibiting biofilm formation, disrupting cell membrane integrity, increasing cell membrane permeability, and altering intracellular Ca2+-Mg2+-ATPase activity. These findings highlight the potential of ZnCA as a promising antibiotic substitute for the treatment of diarrhea in humans.

Highly productive V/Zn-SiO2 catalysts for the selective oxidation of methane

The production of formaldehyde on industrial scale requires huge amounts of energy due to the involvement of reforming processes in combination with the demand in the megaton scale. Hence, a direct route for the transformation of (bio)methane to formaldehyde would decrease costs and puts less pressure on the environment. Herein, we report on the use of zinc modified silicas as possible support materials for vanadium catalysts and the resulting consequences for the performance in the selective oxidation of methane to formaldehyde. After optimization of the Zn content and reaction conditions, a remarkably high space-time yield of 12.4 kgCH2O·kgcat−1·h−1 was achieved. As a result of the extensive characterization by means of UV–vis, Raman, XANES and NMR spectroscopy it was found that vanadium is in the vicinity of highly dispersed zinc atoms which promote the formation of active vanadium species as supposed by theoretical calculations. This work presents a further step of catalyst development towards direct industrial methane conversion which may help to overcome current limitations in the future.

Activation of carbon dioxide on zinc oxide surfaces doped with cerium

AbstractThe adsorption of carbon dioxide on the surfaces of zinc oxide doped with cerium was studied. For this, a theoretical study was carried out using computational simulations based on density functional theory to determine possible improvements in photocatalytic activity. for the capture and dissociation of carbon dioxide. Calculations were performed using density functional theory within the Perdew-Burke-Ernzerhof generalized gradient approximation, also the Hubbard correction together with ultrasmooth atomic pseudopotentials and a basic plane wave implemented in the Quantum-ESPRESSO package. The doping concentration level considered in this work was 6.25%, among the results, the semiconducting character of zinc oxide was evident from the density of states calculations, it was also found that by adding cerium impurities to zinc oxide, the values of the lengths and angles of the bonds vary a little, this may be due to the small difference in covalent radius that the zinc atom has with respect to the cerium atom, consequently, changes occurred in the electronic properties that consist in intermediate states in the energy bandgap located around the Fermi energy. This may suggest that the cerium-doped zinc oxide system can probably absorb visible light, which could lead to possible improvements in the photocatalytic properties of the material. Furthermore, we found that by adding carbon dioxide to the cerium-doped zinc oxide surface, the carbon dioxide is activated and this could suggest the dissociation or reduction of this contaminant.

Bis[μ-bis-(pyridin-2-yl)methanone oxime-κ3N:,N',N'']bis-[di-acetato-κ2O,O';κO-zinc(II)

The structure of the title complex, [Zn2(C2H3O2)4(C11H9N3O)2], is triclinic containing half of the mol-ecule in the asymmetric unit. Each zinc atom is coordinated to a pyridyl and oxime nitro-gen from one di-2-pyridyl ketone oxime (dpko) ligand and a third nitro-gen from the other dpko pyridyl ring. Additionally, each zinc is coordinated to two acetato anions, one of which is bidentate and the other monodentate. The uncoordinated oxygen of the monodentate acetato group is involved in a hydrogen bond with the oxime hydrogen. The packing in the crystal is assisted by weak C-H⋯O inter-actions between acetato groups and neighboring pyridyl rings.

Ca3Ru3Zn13 – a zinc-rich intermetallic phase composed of closest-packed layers

Abstract Ca3Ru3Zn13 was synthesized from the elements in a tantalum tube in a muffle furnace. The sample was annealed to 1123 K followed by slow cooling to enhance crystal growth. Ca3Ru3Zn13 was characterized through a Guinier powder pattern. The structure was refined from single crystal X-ray diffractometer data: new type, Pbcn, a = 522.92(5), b = 1792.72(14), c = 2789.6(2) pm, wR2 = 0.0590, 3451 F 2 values, 177 variables. One can describe the Ca3Ru3Zn13 structure by a stacking of closest packed layers of compositions Ca6Zn10, Ca6Zn12 and Ru6Zn15. The calcium atoms have high coordination numbers: Ca1@Zn13Ru3Ca2, Ca2@Zn15Ru4Ca, Ca3@Zn15Ru4Ca and Ca4@Zn15Ru4Ca. The shortest interatomic distances occur between the ruthenium and zinc atoms (255–273 pm). The Ru1@Zn8, Ru2@Zn10 and Ru3@Zn8 polyhedra condense via common edges to the [Ru3Zn13] substructure which hosts the calcium atoms. The zinc substructure consists of 15 crystallographically independent zinc sites with a broader range of Zn–Zn distances (255–307 pm).

Photoluminescence of Erbium-Doped ZnO Nanostructures

The present work reviews the results of the photoluminescence study of erbium-doped ZnO nanostructures synthesized by physical and chemical methods. ZnO is a semiconductor compound composed of zinc and oxygen atoms. It possesses a wide bandgap (3.37 eV) and is optically and electrically active. When ZnO is synthesized in the form of nanostructures, such as nanoparticles, nanowires, nanorods, nanotubes, or nanosheets, it exhibits enhanced properties compared to its bulk counterpart due to quantum confinement effects and a high surface-to-volume ratio. By controlling different parameters in the growth processes of erbium-doped ZnO nanostructures, materials can be synthesized for different applications such as sensors, optoelectronics, and energy harvesting.

Evaluation of the Electronic Properties of Atomic Layer Deposition-Grown Ge-Doped Zinc Oxide Thin Films at Elevated Temperatures

The aim of this study was to determine the electronic properties of as-deposited ALD-grown Ge-doped zinc oxide thin films annealed at 523 K or 673 K. SEM, EDS, and ellipsometry measurements confirmed that the Ge-doped zinc oxide films with a thickness of around 100 nm and uniform composition were successfully obtained. GI-XRD measurements did not reveal phases other than the expected Wurtzite structure of the ZnO. The electronic properties, i.e., conductivity, charge carrier concentration, and mobility of the films, were evaluated using Hall effect measurements and explained based on corresponding XPS measurements. This work supports the theory that oxygen vacancies act as electron donors and contribute to the intrinsic n-type conductivity of ZnO. Also, it is shown that the effect of oxygen vacancies on the electronic properties of the material is stronger than the effect introduced by Ge doping.