On the Effect of the Co-Introduction of Al and Ga Impurities on the Electrical Performance of Transparent Conductive ZnO-Based Thin Films (original) (raw)
Related papers
Effect of the annealing temperature on transparency and conductivity of ZnO:Al thin films
Thin Solid Films, 2009
Highly aluminum-doped zinc oxide (ZnO:Al) films were grown by rf-magnetron sputtering at low temperature from aerogel nanoparticles and characterized by structural, electrical and optical techniques. Nanoparticles with a size of about 30 nm were synthesized by sol-gel method using supercritical drying in ethyl alcohol and annealed at different temperatures with different gas atmospheres. The ZnO films were polycrystalline textured, preferentially oriented along the (002) crystallographic direction normal to the film surface. The films show within the visible wavelength region an optical transmittance of more than 90% and low electrical resistivity of 10 − 3 Ω cm at room temperature.
Transparent conducting ZnO:Al, In and Sn thin films deposited by the sol–gel method
Thin Solid Films, 2003
The effects of aluminum, indium and tin dopants on the microstructure and electrical properties of ZnO thin films prepared on silica glass substrates by the sol–gel method were investigated. As a starting material, zinc acetate dihydrate was used. 2-methoxyethanol and monoethanolamine were used as the solvent and stabilizer, respectively. The dopant sources were aluminum chloride, indium chloride and tin chloride. For each dopant, films doped with 1 at.% aluminum, 1 at.% indium and 2 at.% tin concentrations exhibited a stronger c-axis orientation perpendicular to the substrate and had larger grain, a high smooth surface morphology as well as high conductivity and transmittance than the others. In addition, the electrical resistivity value of ZnO thin films reduced by applying the second heat-treatment in nitrogen with 5% hydrogen. When the aluminum doping concentration was 1 at.%, the film had a columnar structure, a resistivity value of 1.1×10−2 Ω cm and a transmittance higher than 90% in the visible spectra region.
Design of ZnO/Ag/ZnO multilayer transparent conductive films
Materials Science and Engineering: B, 2006
We have studied the properties of ZnO/Ag/ZnO multilayers prepared on glass substrates by simultaneous RF magnetron sputtering of ZnO and dc magnetron sputtering of Ag. The electrical and optical performance of Ag and ZnO single layer films was also investigated. Different optimization procedures were used for good transparent conductive film. Several analytical tools such as spectrophotometer, scanning electron microscope (SEM), four-point probes were used to explore the causes of the changes in electrical and optical properties. Low sheet resistance of 3 /sq. and transmittance over 90% at 580 nm was achieved. The results of optimization condition of both oxide layers and metallic Ag layers were illustrated.
Applied Sciences, 2021
ZnO thin films with oxygen vacancies and doped with Al, Ga, and In (Zn1-xMxO1−y (x = 0.03)) have been successfully deposited on soda-lime glass substrates using a simple soft chemical method. The crystalline structure shows a single hexagonal phase of wurtzite with preferred crystal growth along the 002 plane. The surface morphology, characterized by SEM, revealed that the grain shape varies depending on the dopant agent used. Optical measurements displayed an increase in the bandgap values for doped films from 3.29 for ZnO to 3.35, 3.32, and 3.36 for Al, Ga, and In doped films, respectively, and an average transmittance superior to 90% in some cases (in the range between 400 and 800 nm). The electrical response of the films was evaluated with a four-point probe being 229.69, 385.71, and 146.94 Ω/sq for aluminium, gallium, and indium doped films, respectively.
Journal of Materials Science: Materials in Electronics, 2014
Al-doped zinc oxide (AZO) thin films are prepared on polycrystalline fluorine-doped tin oxide-coated conducting glass substrates from nitrates baths by the electrodeposition process at 70°C. The electrochemical, morphological, structural and optical properties of the AZO thin films were investigated in terms of different Al concentration in the starting solution. It was found that the carrier density of AZO thin films varied between -3.11 and -5.56 9 10 20 cm -3 when the Al concentration was between 0 and 5 at.%. Atomic force microscopy images reveal that the concentration of Al has a very significant influence on the surface morphology and roughness of thin AZO. X-ray diffraction spectra demonstrate preferential (002) crystallographic orientation having c-axis perpendicular to the surface of the substrate and average crystallites size of the films was about 33-54 nm. With increasing Al doping, AZO films have a strong improved crystalline quality. As compared to pure ZnO, Al-doped ZnO exhibited lower crystallinity and there is a shift in the (002) diffraction peak to higher angles. Due to the doping of Al of any concentration, the films were found to be showing [80 % transparency. As Al concentration increased the optical band gap was also found to be increase from 3.22 to 3.47 eV. The room-temperature photoluminescence spectra indicated that the introduction of Al can improve the intensity of ultraviolet (UV) emission, thus suggesting its greater prospects in UV optoelectronic devices. A detailed comparison and apprehension of electrochemical, optical and structural properties of ZnO and ZnO:Al thin films is done for the determination of optimum concentration of Al doping.
A.C. Conductivity and Dielectric Study of ZnO Thin Films
2014
www.erpublication.org Abstract-Aluminum/ zinc oxide/Aluminum polycrystalline thin films (Al/ZnO/Al) with thickness of 100 nm have been prepared at room temperature by thermal evaporation technique. The films have been annealed at different annealing temperatures (373,423,473) o K. A.C. conductivity σ a.c . (ω) of the prepared thin films has been measured in the frequency range of (0.1 -400) KHz at room temperature. The results reveal that σ a.c (ω) obey the relation σ a.c (ω)= Aω s and the exponent (s) was found to decrease by increasing the temperature. The values of (s) of the investigated thin films lie between 0.77and o 0.86. The data were analyzed in terms of different models of A.C. conduction. It was found that the correlated barrier hopping (C.B.H.) is the dominant conduction mechanism. The dependence of dielectric constant (έ) and loss factor (tan δ) on frequency and annealing temperatures have been analyzed too.
INFLUENCE OF ALUMINUM CONCENTRATION ON THE ELECTRICAL AND OPTICAL PROPERTIES OF ZnO THIN FILMS
Journal of the Turkish Chemical Society, Section A: Chemistry, 2016
Al:ZnO (AZO) thin films having with different Al concentrations were deposited on glass substrates by a sol-gel technique. The effects of Al doping on the structural, optical, and electrical properties of Al:ZnO were investigated using with XRD, optical transmittance, and sheet resistance measurements. The concentration of zinc acetate was 0.1 M. Al content in the starting solution was varied from 0 to 20% as the molarity range. Optical transmittance spectra of the films in the form of Film/Glass were used to determine the film thickness and optical band gaps. The optical transmissions of Al:ZnO thin films were higher than 80% in the visible and near infrared region. The optical band gaps of Al:ZnO films decrease with increase of Al content. In order to obtain the average sheet resistance of the films the current and voltage through the probes have been measured for five different position by four-point probe method. The results showed that the sheet resistances of Al:ZnO thin films increased with the Al concentration. Considering the film thickness and geometric factor, the electrical resistivity values were computed. It was observed that the sheet resistance of AZO films up to 10% molarity of Al in the starting solution increased.
Conductive and transparent ZnO:Al thin films obtained by chemical spray
Journal of Materials Science-materials in Electronics, 2000
Electrical, structural, morphological and optical characteristics of ZnO:Al thin films obtained by chemical spray are presented in this paper. The dependence of the resistivity on the substrate temperature and the film thickness is reported. For the optimized conditions with no post-annealing the lowest resistivity values obtained for ZnO:Al thin films were 1.4 \times 10^{ - 2} \Omega {\text{cm}}$$ for films