Papers by Keyword: Transparent Conducting Oxide (TCO)

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Authors: Chien Chen Diao, Chao Chin Chan, Chia Ching Wu, Cheng Fu Yang
Abstract: “GfE Coating Materials Company” had developed a novel AZOY transparent conducting oxide (TCO) material that used ZnO as raw material and contained a small amount of Y2O3 and Al2O3. In this study, the AZOY material developed by GfE company is used as the based TCO material and we will develop the influences of substrate temperatures on the characteristics of AZOY TCO films by RF sputtering method, under optimal O2/argon ratio and depositing pressure. After deposition, the sheet resistance of AZOY films is measured with a four point probe, and surface morphology and cross-sections are studied using a field emission scanning electron microscope (FESEM). And finally, the UV-Vis spectrophotometer is used to find the transmittance of AZOY TCO films.
Authors: Hassan Noorikalkenari, Karim bin Deraman
Abstract: Solar energy is probably the most important source of renewable energy available today. ZnO is a potential material for the fabrication solar cell. Zinc oxide (ZnO) nano-structure semiconductors have been recently gained much attention in the electronic and optical device applications. ZnO is a compound semiconductor, which has a high extention band gap (E= 3.37 eV) at room temperature (RT) with a Wurtzite crystal structure. In particular ZnO can be employed as the transparent conducting oxide (TCO) in solar cell applications due to its high productivity, non-toxic, low cost, and excellent electrical conductivity. In this study, aluminum doped ZnO (AZO) polycrystalline films have been fabricated on ITO/substrates via a sol-gel spin-coating method. The quantity of aluminum doping in the solution was 4.0 %. After synthesis, the films were pre-heated at 300°C for 25 min and after that the films were inserted in a Tub-furnace and post-annealing at 450°C to 750°C for 1 h. The microstructural and structural properties of AZO films were studied through X-ray diffraction (XRD), UV-Vis NIR and scanning electron microscope (SEM) analysis. The TCO applications of the transmittance of samples were also examined. The results showed that the annealing temperature does not seriously affect on the transmittance of AZO films over the visible range.
Authors: D. Briand, M. Sarret, T. Mohammed-Brahim, S. Mottet, O. Bonnaud
Authors: Hong Yun Yue, Ai Min Wu, Juan Hu, Xue Yu Zhang, Ting Ju Li
Abstract: ZnO:Al thin films were deposited on glass substrates by r. f. magnetron sputtering. The crystal structures were characterized using X-ray diffraction. The electrical property and the light transmission of the ZnO:Al thin films were investigates utilizing Hall system and UV/Vis/NIR spectrophotometer. The results show that the ZnO:Al thin films prepared with the sputtering power of 100W, working pressure of 0.3Pa and substrate temperature of 250°C have the resistivity as low as 3.1×10-3Ω⋅cm and transmittance over 90% in visible region. From the GIXRD patterns, higher electrical conductivity is related to the higher ratio of I2 (103)/I(002), which is a new reasonable structure parameter to estimate the electrical property of ZnO:Al thin films.
Authors: Leandro Raniero, Alexandra Gonçalves, Ana Pimentel, Shibin Zhang, Isabel Ferreira, Paula M. Vilarinho, Elvira Fortunato, Rodrigo Martins
Abstract: In this work we studied the influence of the power density of hydrogen plasma on electrical and optical properties (Hall mobility, free carrier concentration, sheet resistance, optical transmittance and a.c. impedance) of indium zinc oxide films, aiming to determine their chemical stability. This is an important factor for the optimization of amorphous/nanocrystalline p-i-n hydrogenated silicon (a/nc-Si:H) solar cells, since they should remain chemically highly stable during the p layer deposition. To perform this work the transparent conductive oxide was exposed to hydrogen plasma at substrate temperature of 473 K, 87 Pa of pressure and 20 sccm of hydrogen flow. The results achieved show that IZO films were reduced for all plasma conditions used, which leads mainly to a decrease on films transmittance. For the lowest power density used in the first minute of plasma exposition the transmittance of the IZO films decreases about 29%.
Authors: C. Oliveira, Carlos M. Costa, L. Rebouta, T. Viseu, T. de Lacerda-Arôso, Senentxu Lanceros-Méndez, Eduardo Alves
Abstract: Transparent conducting Al doped ZnO films have been deposited by dc magnetron sputtering on glass and polymer substrates at room temperature. Depositions have been carried out from an AZOY (contains a small amount of Y2O3 in addition to Al2O3 and ZnO) target under different conditions such as working pressure, substrate bias voltage and oxygen flow rate. The crystallinity of the Al doped ZnO films has been improved by using low-energy-ion bombardment. Likewise, the use of either the rotation or the static mode of the substrate during deposition influences the crystallinity and therefore the optical parameters and the electrical resistance of the films. Increasing the thickness of the films reduces the threshold strain at which the films can be deformed without provoking significant changes on their electrical properties.
Authors: Satyesh Kumar Yadav, Satya Vyas, Ramesh Chandra, G.P. Chaudhary, S.K. Nath
Abstract: This paper establishes DC reactive magnetron sputtering as synthesis process for Zr doped ZnO thin film. Zr can be doped in ZnO using various techniques. Some research groups have doped ZnO with Zr by radio frequency magnetron sputtering using target made of ZnO and ZrO2 powder. Radio frequency has low rate of deposition because deposition takes place only in one of two half cycles. Uniform mixing of small amount of ZrO2 powder in ZnO is expensive process as well as time consuming. To overcome the constraints, Zn and Zr metal target was used and film was made by DC reactive magnetron sputtering. Various parameters of the process was established by varying variables, such as sputtering power of the Zn and Zr, oxygen partial pressure in the chamber. Optimum flow rate of Argon is 16 sccm and Oxygen is 4 sccm. Sputtering power of 150 watt for Zn and 10 watt for the Zr gives good result. Films obtained are polycrystalline with a hexagonal structure and have preferred orientation along the c axis. Resistivity of the film is as low as 0.07 Ω-cm. Average transparency of film is above 85% in visible range.
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