high-priced metals doped ITO transparent conductive film studies

Title: high-priced metals doped ITO transparent conductive film studiesAuthor: BoDegree-granting units: Shanghai Jiaotong UniversityKeywords: transparent conductive oxide;; magnetron sputtering;; microstructure;; optical properties;; optical band gap;; first-principles calculationsSummary:Since the 1990s, advances in flat panel display technology to promote the development of optical thin films. Because of its high carrier concentration and optical band gap wider, transparent conductive oxide films showed good optical properties, such as low resistivity and high visible light transmittance. One, ITO (Sn-doped In2O3) films because of its good optical properties and are widely used in transparent electrodes. But the ITO films as well as chemical and thermal neodymium magnets stability, low surface energy does not limit the application of ITO films, while its optical performance but also to further improve and enhance the overall performance of ITO films is an important direction of current research. In this paper the use of magnetron sputtering of indium oxide-based multi-component oxide thin films. At the same time, the use of first-principles calculations of the electronic band structure.The performance of ITO films depends on its oxidation state and doping concentration, carrier concentration can be adjusted by doping, doping donor atoms can be replaced by free electrons and provide increased carrier concentration. In this article, zirconium and tantalum can be used as dopant donor atoms to achieve an effective substitute, thus releasing free electrons increase the conductivity of thin films. Zirconium and tantalum-doped ionic radius than indium ions, can achieve a limited solid solution. In order to achieve high effective doping metallic elements, including the http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php use of the DC and RF power of dual-target sputtering system, were used co-sputtering process of ITO target, Zr target and Ta2O5 target.The use of magnetron sputtering deposited on glass substrate ITO, ITO: Zr and ITO: Ta thin films, effects of different experimental parameters on the thin-film photovoltaic performance. The results show that high prices for metals doped ITO films crystallized at the same time, leading to (400) crystal plane preferred orientation formation. Low temperature deposition of ITO: Zr and ITO: Ta films than ITO films showed good optical properties, Zr, Ta-doped ITO films deposited at room temperature makes the benefits of index by 0.003 × 10-3Ω-1 rose to 0.15 × 10 - 3Ω-1 and 0.88 × 10-3Ω-1. Improve the substrate temperature can significantly improve the optical properties of thin films; excessive oxygen flow rate will deteriorate the transparency film; appropriate annealing the film's optical performance is improved, high temperature annealing in air has reduced the electrical properties of thin films. Transmission spectra indicate changes in the parameters of a clear "Burstin-Moss" effect, through direct transition model to study the changes in the optical band gap. Total sputtering of ITO: Zr and ITO: Ta films than ITO films showed good optical performance and a wide optical band gap. In the same preparation conditions, ITO: Ta thin film was slightly lower than the resistance of ITO: Zr films, but the ITO: Ta thin film visible light transmittance than ITO: Zr films.Using first-principles calculations based on indium oxide transparent conductive oxide of electronic band structure. Band structure of the valence band top and conduction band have a major impact on optical performance. Used in the calculation of the dopant atoms in the lattice instead of a more stable position In1 can be found: the valence band top mainly from O 2p and In 4d states contribute to the conduction band bottom mainly from In 5s and Sn 5s states (and Zr 4d, Ta 5d) contribution. Incorporation of dopant atoms caused the Fermi level and conduction band bottom and top of valence band offset, which is the high intrinsic optical properties of doped materials, the reason for improvement.According to the media environment in particular the relative change in resistance ITO film and surface analysis, doped ITO film shows good chemical stability and thermal stability. In addition to crystal structure, the better stability of zirconia and tantalum oxide films are also improved chemical stability and thermal stability. Based on the film surface contact angle measurements, calculated the film's surface energy and polarity in the experimental data and calculated results show that doping makes the film the contact angle decreases, the surface energy increases, the degree of surface polarity increased. Film and the surface state near the Fermi level at the high activity of the d orbitals into the existence of atoms is the main reason for increased surface energy.Degree Year: 2009