Zirconium-doped Zinc Oxide Research Articles

Comparative study of zirconium-zinc oxide thin films on ceramic and glass substrates: Structural, optical, and photocatalytic properties

This study investigates the structural, optical, and photocatalytic properties of zirconium-doped zinc oxide (Zr) thin films deposited on ceramic and glass substrates. X-ray diffraction (XRD) analysis revealed that all samples exhibited a polycrystalline wurtzite structure, with grain sizes ranging from 25 to 43 nm for ceramic substrates and 19 to 32 nm for glass substrates. UV–visible absorbance measurements indicated that Zr films absorbed visible light around 410 nm, with the band gap widening to 2.93 eV on ceramic substrates. Scanning electron microscopy (SEM) showed that Zr doping significantly affected the morphology of thin films, resulting in rougher surfaces and larger grains on ceramic substrates. Photocatalytic tests demonstrated that the 5 wt% Zr on DD1Z ceramic achieved a degradation efficiency of 61.44 % for orange II dye after 5 h of UV irradiation. In contrast, Zr on ceramic substrates achieved only 18.56 %, and the bare DD1Z substrate reached just 4.02 %. These findings highlight the superior photocatalytic performance of Zr on ceramic substrates, indicating their potential for advanced water purification technologies. The mechanism of photolysis was investigated using hole/radical scavengers, revealing that Zr-ZnO networks enhance the adsorption of hydroxyl ions on the surface. This acts as a trap site, reducing hole/electron pair recombination and thus increasing activity and photodegradation efficiency.

Zirconium doped zinc oxide thin films grown by spray pyrolysis technique for TCO applications

Zirconium (Zr) doped Zinc Oxide (ZnO) thin films were grown on pre-cleaned glass substrates by spray pyrolysis technique. The dopant was added in different concentrations to study its influence on the structural, optical, morphological, and electrical properties of ZnO thin films. X- Ray Diffractogram (XRD) data was used to study the structural properties of all the thin films. It was found that the crystallite size varied between 25 and 45 nm for dopant at different concentrations. Additionally, it was discovered that ZnO possessed a hexagonal wurtzite structure with (002) as its preferred orientation regardless of the doping doses. The optical properties for all the thin films were obtained by analysing the absorption spectra. The transmittance of all the thin films ranged between 65 % and 86 % in the visible range with 4 at % Zr doped ZnO having highest transmittance. Scanning Electron Microscopy (SEM) results showed the agglomeration of particles at higher concentrations of the dopant. Electrical studies showed that the resistivity of the doped samples decreased as compared to the pristine sample. Sample with 6 % of doping had the highest carrier concentration and hence, showed the least resistivity of 67 Ω cm.

Zr-doped ZnO nanohybrid via glycine mediated sol–gel approach as benign supporter for degradation of Crystal violet and antibacterial performance

The current work describes the preparation of zirconium-doped zinc oxide (Zr/ZnO) nanohybrid through sol–gel approach fascinated by combustion process with glycine as a fuel. The analytical instruments were used including FTIR, XRD, XPS, SEM, BET and TGA for studying the optical and structural properties of prepared nanohybrid. The characterized Zr-ZnO nanohybrid exhibited lesser size (18 nm) than pure ZnO (24 nm). This could be a lead to possess more catalytic activity towards the degradation of dye pollutants and inactivation of pathogens. The photocatalytic performance was executed by the degradation of Crystal violet (CV) dye under visible light irradiations, the complete degradation was achieved in 90 min. The optimum reaction conditions are 0.1 g catalyst dose, pH-2, and 10 ppm dye concentration. To extent on catalytic performance, the antimicrobial study was further carried out by Vibrio cholera, and Clostridium perfringes. The results declared that prepared nanohybrid was the most effective for antimicrobial performance.

Tailoring the Structural, Optical and Electrical Properties of Zinc Oxide Nanostructures by Zirconium Doping

Owing to its low resistivity, high transmittance, and tunable optical band gap, ZnO is of great interest for optoelectronic applications. Herein, the sol–gel technique was used to synthesize un-doped and zirconium-doped zinc oxide (ZZO) nanostructures with different concentrations of Zirconium (Zr). X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, and photoluminescence (PL) measurements were used to investigate the influence of Zr doping on the structural, optical, and electrical properties of developed nanostructures. XRD and SEM confirmed the increase in crystallite size with increasing concentrations of Zr. Raman analysis indicated the presence of oxygen vacancies in synthesized nanostructures. UV-Vis spectroscopy illustrated the blue shift of band gap and red shift of the absorption edge for ZZO nanostructures with increasing concentrations of Zr. For the measurement of electrical properties, the spin-coating technique was used to deposit un-doped and Zr-doped ZnO layers of ~165 nm thickness. The four-probe-point (4PP) method illustrated that the doping of Zr caused a reduction in electrical resistance. Hall Effect measurements showed a high value, 3.78 × 1020 cm−3, of the carrier concentration and a low value, 10.2 cm2/Vs, of the carrier mobility for the Zr-doped layer. The high optical transmittance of ~80%, wide band gap of 3.51 eV, low electrical resistivity of 1.35 × 10−3 Ω·cm, and maximum carrier concentration of 3.78 × 1020 cm−3 make ZZO nanostructures one of the most promising candidates for the application of transparent conductive oxide (TCO) in optoelectronic devices.

Photocatalytic degradation of water disinfection by-products using zirconium doped zinc oxide nanoparticles

Photocatalytic degradation of water disinfection by-products using zirconium doped zinc oxide nanoparticles

Zirconium-Doped Zinc Oxide Nanoparticles as Cathode Interfacial Layers for Efficiently Rigid and Flexible Organic Solar Cells.

Low-temperature zinc oxide nanoparticles (ZnO NPs) are widely applied as cathode interfacial layers (CILs) for rigid and flexible organic solar cells. However, the inferior optoelectronic properties of ZnO NPs constrain the improvement in the photovoltaic performance and enhance the thickness sensitivity. Herein, upon application of this ZnO:Zr NP as a CIL for inverted device construction, the maximum power conversion efficiency (PCEmax) is increased to 17.7%, with an enhancement of 12.0% compared to that of the pristine ZnO-based devices (15.8%). A series of optoelectronic characterizations have revealed that the Zr doping methodology would enhance the charge generation and extraction process and suppress trap-assisted recombination, which is beneficial for the synergistic improvement of the thickness tolerance and shelf stability. Encouragingly, ZnO:Zr NPs can be easily fabricated through a doctor-blade coating technique with remarkable performance (16.6%). More critically, this approach can be applied to the development of high-performance flexible solar cells, with a superb PCE of 16.0%.

Effects of Rapid Thermal Annealing on the Structural, Electrical, and Optical Properties of Zr-Doped ZnO Thin Films Grown by Atomic Layer Deposition.

The 4 at. % zirconium-doped zinc oxide (ZnO:Zr) films grown by atomic layer deposition (ALD) were annealed at various temperatures ranging from 350 to 950 °C. The structural, electrical, and optical properties of rapid thermal annealing (RTA) treated ZnO:Zr films have been evaluated to find out the stability limit. It was found that the grain size increased at 350 °C and decreased between 350 and 850 °C, while creeping up again at 850 °C. UV–vis characterization shows that the optical band gap shifts towards larger wavelengths. The Hall measurement shows that the resistivity almost keeps constant at low annealing temperatures, and increases rapidly after treatment at 750 °C due to the effect of both the carrier concentration and the Hall mobility. The best annealing temperature is found in the range of 350–550 °C. The ZnO:Zr film-coated glass substrates show good optical and electrical performance up to 550 °C during superstrate thin film solar cell deposition.

The optical and electrical properties of ZnO:Zr films

Zirconium doped zinc oxide (ZnO:Zr) films at different Zr doping concentrations were deposited by radio frequency (RF) reactive magnetron sputtering. The effect of Zr contents on the crystalline structure, optical and electrical properties of the as-deposited ZnO:Zr films were systematically investigated. The results showed that ZnO:Zr film for 0.51 at% had a stronger preferred orientation toward the c-axis and a better crystallinity which were be good for UV photosensitivity. The lowest resistivity of 31.8 Ω cm was obtained for 0.51 at% Zr doped ZnO film. The UV photosensitivity showed that photodetectors based on ZnO:Zr film for 0.51 at% had very fast response and a higher photocurrent under UV illumination, which was attributed to the release of trapped electrons from surface defects or adsorbed oxygen. The photosensitivity mechanism of ZnO:Zr films has been also discussed in present paper.

Comparative Study of the Properties between Transparent Conducting ZnO:Zr and ZnO:Al Films Deposited by DC Magnetron Sputtering

Transparent conducting zirconium-doped zinc oxide (ZnO:Zr) and aluminium-doped zinc oxide (ZnO:Al) thin films were deposited on glass substrates by direct current (DC) magnetron sputtering at room temperature. The crystallinity of ZnO:Zr and ZnO:Al thin films increases as the target-to-substrate distance decreases, and the crystallinity of ZnO:Zr films is found to be always better than that of ZnO:Al films prepared under the same deposition conditions. As the target-to-substrate distance decreases, the resistivity of both film types decreases greatly while the optical transmittance does not change much with the variation of the distance. When target-to-substrate distance is 4.1 cm, the lowest resistivity of 6.0×10-4 Ω·cm and 5.7×10-4 Ω·cm was obtained for ZnO:Zr and ZnO:Al films, respectively. The figure of merit arrived at a maximum value of 3.98×10-2Ω for ZnO:Zr films lower than 5×10-2 Ω for ZnO:Al films.

Investigation on the effect of Zr doping in ZnO thin films by spray pyrolysis

Zirconium doped zinc oxide thin films with enhanced optical transparency were prepared on Corning 1737 glass substrates at the substrate temperature of 400 °C by spray pyrolysis method for various doping concentrations of zirconium (IV) chloride in the spray solution. The X-ray diffraction studies reveal that the films exhibit hexagonal crystal structure with polycrystalline grains oriented along (0 0 2) direction. The crystalline quality of the films is found to be deteriorating with the increase of doping concentration and acquires amorphous state for higher concentration of 8 at.% in precursor solution. The average transmittance for 5 at.% (solution) zirconium doped ZnO film is significantly increased to ∼92% in the visible region of 500–800 nm. The room temperature photoluminescence (PL) spectra of films show a band edge between 3.41 and 3.2 eV and strong blue emission at 2.8 eV irrespective of doping concentration and however intensity increases consistently with doping levels. The vacuum annealing at 400 °C reduced the resistivity of the films significantly due to the coalescence of grains and the lowest resistivity of 2 × 10 −3 Ω cm is observed for 3 at.% (solution) Zr doped ZnO films which envisages that it is a good candidate for stable TCO material.

Characteristics of Zr-Doped ZnO Thin Films Grown by Atomic Layer Deposition

In the study, we present the electrical and optical properties of zirconium-doped zinc oxide (ZnO:Zr) thin films grown by atomic layer deposition (ALD) on sapphire substrates. The ZnO:Zr films exhibited low resistivity (1.3 × 10−3 Ω cm), high carrier concentration (2.2 × 1020 cm−3), and high transparency (> 92%) in the visible spectrum. The photoluminescence spectra consisted of a strong spontaneous emission at 380 nm associated with the near-band-edge emission and a weak defect-related band. Optically-pumped stimulated emission in ZnO:Zr films was achieved with a low threshold intensity of 105 kW/cm2 at room temperature. The results indicate that the ZnO:Zr films prepared by ALD are applicable to transparent conductive oxide and ultraviolet light-emitting materials.

Influence of annealing temperature on the properties of ZnO:Zr films deposited by direct current magnetron sputtering

Transparent conducting zirconium-doped zinc oxide (ZnO:Zr) films were deposited on quartz substrates by direct current (DC) magnetron sputtering at room temperature. The influence of post-annealing temperature on the structural, morphological, electrical and optical properties of ZnO:Zr films were investigated. When annealing temperature increases from room temperature to 573 K, the resistivity decreases obviously due to an improvement of the crystallinity. However, with further increase in annealing temperature, the crystallinity deteriorates leading to an increase in resistivity. The films annealed at the optimum annealing temperature of 573 K in vacuum have the lowest resistivity of 9.8 × 10 −4 Ω cm and a high transmittance of above 92% in the visible range.

Effects of deposition temperature on the surface roughness and the nonlinear optical susceptibility of sprayed deposited ZnO:Zr thin films

Zirconium doped zinc oxide thin films were deposited by reactive chemical pulverization spray pyrolysis technique on heated glass substrates at 400 °C, 450 °C and 500 °C using zinc and zirconium chlorides as precursors. The effect of zirconium dopant and surface roughness on the nonlinear optical properties was investigated using atomic force microscopy (AFM) and third harmonic generation (THG). The best value of susceptibility χ (3) was obtained from the doped films with less roughness. A strong third order nonlinear optical susceptibility χ (3) = 20.49 × 10 −12 (esu) of the studied films was found for the 5% doped sample at 450 °C.

Thickness dependence of the properties of transparent conducting ZnO:Zr films deposited on flexible substrates by RF magnetron sputtering

Transparent conducting zirconium-doped zinc oxide (ZnO:Zr) thin films with high transparency, low resistivity and good adhesion were successfully prepared on water-cooled flexible substrates (polyethylene glycol terephthalate, PET) by RF magnetron sputtering. The structural, electrical and optical properties of the films were studied for different thicknesses in detail. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that all the deposited films are polycrystalline with a hexagonal structure and a preferred orientation perpendicular to the substrate. The lowest resistivity achieved is 1.55 × 10−3 Ω·cm for a thickness of 189 nm with a Hall mobility of 17.6 cm2/(V·s) and a carrier concentration of 2.15 × 1020 cm−3. All the films present a high transmittance of above 90% in the wavelength range of the visible spectrum.

Influence of the sputtering pressure on the properties of transparent conducting zirconium-doped zinc oxide films prepared by RF magnetron sputtering

Transparent conducting zirconium-doped zinc oxide films with high transparency and relatively low resistivity have been successfully prepared on water-cooled glass substrate by radio frequency magnetron sputtering at room temperature. The Ar sputtering pressure was varied from 0.5 to 3 Pa. The crystallinity increases and the electrical resistivity decreases when the sputtering pressure increases from 0.5 to 2.5 Pa. The cystallinity decreases and the electrical resistivity increases when the sputtering pressure increases from 2.5 to 3 Pa. When the sputtering pressure is 2.5 Pa, it is obtained that the lowest resistivity is 2.03 × 10−3 Ω·cm with a very high transmittance of above 94%. The deposited films are polycrystalline with a hexagonal structure and a preferred orientation perpendicular to the substrate.

Low-temperature deposition of transparent conducting ZnO:Zr films on PET substrates by DC magnetron sputtering

Transparent conducting zirconium-doped zinc oxide (ZnO:Zr) films were firstly deposited on polyethylene terephthalate (PET) substrates with ZnO buffer layers by DC magnetron sputtering at room temperature. Dependence of physical properties of ZnO:Zr films on deposition pressure was systematically studied. All the deposited films were polycrystalline and (1 0 0) oriented. When deposition pressure increases from 1 to 2.5 Pa, the crystallinity of the films improves and the resistivity decreases. While deposition pressure increases from 2.5 to 3.5 Pa, the crystallinity of the films deteriorates and the resistivity increases. The lowest resistivity of 1.8 × 10 −3 Ω cm was obtained for the films deposited at the optimum deposition pressure of 2.5 Pa. All the films present a high transmittance of above 86% in the wavelength range of the visible spectrum.

Diagnostic study of the roughness surface effect of zirconium on the third-order nonlinear-optical properties of thin films based on zinc oxide nanomaterials

Zinc oxide (ZnO) and zirconium doped zinc oxide (ZnO:Zr) thin films were deposited by reactive chemical pulverization spray pyrolysis technique on heated glass substrates at 500 °C using zinc and zirconium chlorides as precursors. Effects of zirconium doping agent and surface roughness on the nonlinear optical properties were investigated in detail using atomic force microscopy (AFM) and third harmonic generation (THG) technique. The best value of nonlinear optical susceptibility χ (3) was obtained from the doped films with less roughness. A strong third order nonlinear optical susceptibility χ (3) = 20.12 × 10 −12 (esu) of the studied films was found for the 3% doped sample.

Theoretical study of structural, optical and electrical properties of zirconium-doped zinc oxide

The structural, optical and electrical properties of zirconium-doped zinc oxide have been investigated by first principle calculations. Three possible structures including substitutional Zr for Zn (Zr Zn), interstitial Zr (Zr i) and substitutional Zr for O (Zr O) are considered. The results show that the formation energy of Zr Zn defect is the lowest, which indicates that Zr Zn defect forms easier and its concentration may be the highest in the samples. It is also found that as the proportion of Zr increases, the lattice constants increase while the optical band gap first becomes larger and then smaller, which are consistent with our recently experimental results. The electronic structure calculations display that as Zr Zn defect is introduced into ZnO, the Fermi-level shifts to the conduction band, and there are excess electrons in the conduction band, which may be a possible reason of the good conductivity of Zr doped ZnO film.

Structural, electrical and optical properties of zirconium-doped zinc oxide films prepared by radio frequency magnetron sputtering

Transparent and conducting zirconium-doped zinc oxide films have been prepared by radio frequency magnetron sputtering at room temperature. The ZrO 2 content in the target is varied from 0 to 10 wt.%. The films are polycrystalline with a hexagonal structure and a preferred orientation along the c axis. As the ZrO 2 content increases, the crystallinity and conductivity of the film are initially improved and then both show deterioration. Zr atoms mainly substitute Zn atoms when the ZrO 2 content are 3 and 5 wt.%, but tend to cluster into grain boundaries at higher contents. The lowest resistivity achieved is 2.07 × 10 − 3 Ω cm with the ZrO 2 content of 5 wt.% with a Hall mobility of 16 cm 2 V − 1 s − 1 and a carrier concentration of 1.95 × 10 20 cm − 3 . All the films present a high transmittance of above 90% in the visible range. The optical band gap depends on the carrier concentration, and the value is larger at higher carrier concentration.

Effect of RF power on the properties of transparent conducting zirconium-doped zinc oxide films prepared by RF magnetron sputtering

Transparent and conducting zirconium-doped zinc oxide films with high transparency and relatively low resistivity have been successfully prepared by radio frequency (RF) magnetron sputtering at room temperature. The RF power is varied from 75 to 150 W. At first the crystallinity and conductivity of the film are improved and then both of them show deterioration with the increase of the RF power. The lowest resistivity achieved is 2.07×10−3Ω cm at an RF power of 100 W with a Hall mobility of 16 cm2V−1s−1 and a carrier concentration of 1.95×1020 cm−3. The films obtained are polycrystalline with a hexagonal structure and a preferred orientation along the c-axis. All the films have a high transmittance of approximately 92% in the visible range. The optical band gap is about 3.33 eV for the films deposited at different RF powers.