Papers by Keyword: AZO

Abstract: The synthesis and characterization of spin-coated Al-doped ZnO (AZO) thin films with varying Al concentrations (0%, 5%, 10%, 15% and 20%) onto glass substrates have been demonstrated in this paper. The structural, electrical and optical properties of the spin-coated thin films have been investigated by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX) analysis, Van Der Pauw method and UV-visible spectroscopy. The EDX study shows well-defined peaks which confirm the presence of only Zn, O and Al and no other impurities in the films. The increase of Al and decrease of Zn weight percentages with increasing doping level confirms the effective substitution of Zn by Al. SEM of the surfaces of the films shows that undoped ZnO films contain particle agglomeration which is reduced with Al doping and the surfaces of the films gradually became more uniform. The thickness of the AZO films varied from 86 to 699 nm with increasing Al doping concentration. The electrical conductivity of the films increased up to ~ 7 × 10^-2 (Ω.cm)^-1 due to doping with 5% Al concentration. The optical transmittance highly increased above 95% in the visible range with the introduction of Al dopant and it kept rising with the increase of Al concentration. The optical energy band gap of undoped ZnO increased from 3.275eV to 3.342 eV with 5% Al doping.

Abstract: The rise of antimicrobial resistance for infectious bacteria has become an alarming issue to human health. New antimicrobial drugs are in dire need and pivotal to overcome this issue. In this study, aspirinate azo ligands bearing different halogens L1-5 has been prepared via diazo-coupling reaction. The ligands L1-5 were coordinated with silver, Ag (I) metal to produce Ag (I) aspirin-azo complexes C1-5. The antibacterial properties of L1-5 and C1-5 were evaluated against Staphylococcus aureus and Escherichia coli using turbidimetric kinetic method. The complexes C1-5 showed comparable growth inhibition activity towards E. coli (MIC 82-105 ppm) and S. aureus (MIC 80-105 ppm) compared to ligands L1-5 with E. coli (MIC 83-200 ppm), S. aureus (80-131 ppm) and ampicillin (MIC 93 and 124 ppm, respectively). The excellent bacterial resistance of both L1-5 and C1-5 indicates the potential of aspirinate azo and their complexes as new antibacterial agents, which significantly benefit to the pharmaceutical industries.

Abstract: This paper investigates the dependence of pressure onto characteristic of Aluminium Zinc Oxide (AZO) thin films. Films were deposited on a glass substrate by RF Magnetron Sputtering using AZO ceramic target with 99.99% purity. Sputtering was performed with RF power of 100 Watt and the deposition times were fixed at 40 minutes. The argon pressures were varied from 10 sccm to 30 sccm in order to achieve different working pressure during deposition in order to study the effect of pressure towards characteristic of films. AZO thin films on different argon pressure were successfully deposited onto glass substrate. All films are polycrystalline with (0 0 2) preferential orientation and fully transparent films with high transparency above 80 percent were achieved. The film deposited at 10 sccm argon flow exhibit the highest growth rate at 7.9 nm/m, highest intensity XRD peak with higher crystalline quality and lowest resistivity that is 2.7 x 10^ˉ2 Ω cm .

Abstract: We have studied the structural, electrical and optical properties of Al-doped Zinc Oxide (ZnO) nanostructures deposited on glass substrate by chemical bath deposition method. Scanning electrom microscope images clearly reveal that AZO nanorods were successfully grown. The XRD analysis indicates that polycrystalline nature of ZnO nanorods. The calculated grain size is about 84 nm. Electrical resistivity measurement study showes the minimum d.c. resistivity of 3.216×10^-4 Ω.cm was obtained for the AZO films sintered at 300°C. It gives AZO can be adopted as a transparant conductive oxide (TCO) material. Optical transmission spectra showes that more than 80% transmission and 3.47 eV optical band gap of harvested AZO films. It is a potential candidate for ligth emitting diodes (LEDs), photonic crystals, TCO and photovoltaic application.

Abstract: This work characterizes the mechanical and opto-electric properties of Aluminum-doped zinc oxide (AZO) thin films deposited by atomic layer deposition (ALD), where various depositing temperature, 100, 125, 150, 175, and 200 °C are considered. The transmittance, microstructure, electric resistivity, adhesion, hardness, and Young’s modulus of the deposited thin films are tested by using spectrophotometer, X-ray diffraction, Hall effect analyzer, micro scratch, and nanoindentation, respectively. The results show that the AZO thin film deposited at 200 °C behaves the best electric properties, where its resistance, Carrier Concentration and mobility reach 4.3×10^-4 Ωcm, 2.4×10²⁰ cm^-3, and 60.4 cm²V^-1s^-1, respectively. Furthermore, microstructure of the AZO films deposited by ALD is much better than those deposited by sputtering.

Abstract: This paper summarize the transparent conductive oxide (TCO) market application of aluminum doped most widely used in the film Zinc Oxide AZO and ITO thin films and the development trend is prospected. Reports the photoelectric properties of ITO films requirements, prepared on flexible substrate ZnO films on the substrates, preparation technology and development, summarizes the latest research achievements in this field and the present problems, which describes the next step of work in the domain.

Abstract: Aluminium doped zinc oxide (AZO) is fast becoming an important thin film material for applications as transparent conducting oxide (TCO) in several thin film solar cells, smart windows and many devices using touch screen displays. This is due to its good electrical and optical characteristics as well as lower cost and good abundance. Although sputtering is the general method for industrial fabrication of this material, but film characteristics depend strongly on fabrication processes. Thus, optimal films are obtained by optimization of the deposition conditions. In this work, we investigated the effects of RF deposition power on AZO thin films. Samples of similar thicknesses were grown under similar conditions in an RF sputtering chamber at different RF powers. The samples were then characterized using FESEM, AFM, UV-Vis, XRD and Hall effect measurement tools. Results indicate that the surface morphology is slightly affected with larger grain sizes obtained at higher RF powers. Also the surface roughness, average transmittance, conductivity and deposition rate all increase with the RF power. The lowest as-deposited resistivity of 15.3x10^-3 Ω/cm was obtained, at the highest RF power of 100 W. This film also have the highest values of carrier concentration, mobility and figure of merit of 4.24x10²⁰ cm^-3, 0.96 cm²/V and 0.27x10^-3 Ω respectively. This work highlights the significance of RF power in the fabrication of good quality AZO thin films.

Abstract: Ferrocene is a well-known electron donor due to its chemical stability and redox behaviour. By introducing azo dye as an acceptor in the system, the characteristics of azo-ferrocene (AF) compound as a semiconductor material have been investigated. A single layer film of AF compound was deposited on an indium tin oxide (ITO) glass substrate by electrochemical method in the potential range of 0.4 V to 0.8 V. Electrical conductivity of the thin film was investigated using a four-point probe and I-V characteristic of the diode was determined via a two-point probe method. AF material showed an average electrical conductivity of 0.246 ± 0.003 Scm^-1. The forward current-voltage measurement demonstrated a bias voltage in the range of 0.87 V to 10.0 V, and the backward current-voltage measurement indicated a bias voltage in the range of-0.87 V to-7.0 V. In both forward and backward voltages, the current showed a slow increase beyond the readings of 10.0 V to-7.0 V.

Abstract: In this study, a 1350oC-sintered 98 mol% ZnO-1 mol% Al₂O₃ (AZO, Zn:Al= 98:2) ceramic was used as a target and deposited on glass using a r.f. magnetron sputtering system at a deposition temperature of 200°C. The effects of different H₂ flow rates (H₂/(H₂+Ar)=0% ~ 9.09%, abbreviated as H₂-deposited AZO films) added during the deposition process on the crystallization, resistivity, and optical transmission spectrum of AZO films were investigated. The Burstein-Moss shift effects were measured and used to prove that the defects of AZO films decreased with increasing H₂ flow rate. For comparison, the 2% H₂-deposited AZO films were also treated by the H₂ plasma at room temperature for 60 min (plasma-treated AZO films). The effects of H₂ plasma on the properties of the H₂-deposited AZO films were also studied. The value variations in the optical band gap (E_g) of the H₂-deposited and plasma-treated AZO films were evaluated from the plots of (αhv)² = c (hν-E_g).

Abstract: Ti doped aluminum zinc oxide thin film was prepared by DC reaction magnetron sputtering method on the transparent glass substrates. The structure and thermoelectric performance of the deposited (TAZO) thin films are studied by various methods. XRD pattern shows that the TAZO thin film exhibits hexagonal wurtzite structure. After Ti-doping, the thermoelectric properties of TAZO thin film significantly improved at room temperature. The TAZO thin film has the maximum conductivity of 8.33×10⁴ S/m and the Seebeck coefficient absolute value of 34 μV/K, which is respectively larger than that of the corresponding values.