VNU-UET Repository: No conditions. Results ordered -Date Deposited. 2024-03-29T05:49:26ZEPrintshttp://eprints.uet.vnu.edu.vn/images/sitelogo.pnghttps://eprints.uet.vnu.edu.vn/eprints/2017-11-16T04:26:31Z2017-11-16T04:26:31Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/2633This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/26332017-11-16T04:26:31ZSTUDY ON ITO THIN FILMS PREPARED BY
MULTI-ANNEALING TECHNIQUEIndium tin oxide (ITO) thin films have been successfully prepared by a solution process
followed by a multi-annealing method. In this study, we focus on the use of multi-annealing
method, for which each layer was annealed at a suitable temperature, instead of a conventional
annealing way, by means of a rapid thermal annealing system, in order to improve the film
quality. The crystalline structure and surface morphology of the ITO thin films were investigated
by using X-ray diffraction (XRD) spectrometer, atomic force microscope (AFM) and scanning
electron microscope (SEM). It has been obtained that all of ITO films exhibit a single phase with
(200)- and (444)-preferred orientations. The AFM and SEM observations show that the particle
size of ITO films was about 10 nm and the ITO film thickness was 180 nm, respectively. In
sequence, the electrical properties of ITO thin films were evaluated by using four-point probe
and Hall effect measurement methods, and the optical properties were investigated by UV/VIS
spectrometer. The achievement results show that the optimum ITO films possessed electrical
resistivity of 2.6 × 10-3 Ωcm and transparency higher than 90%, which strongly supports to the
application of electrode in solar cell, LED or transistor devices from viewpoints of low-cost
production and low-energy consumption.Quang Hoa NguyenThi Xuyen NguyenQuoc Viet VuongThi Huyen Trang VuHa HoangThi Thanh Tam HoangThi Dung VuVan Dung TranNguyen Quoc Trinh Buitrinhbnq@vnu.edu.vn2017-11-16T04:26:10Z2017-11-16T04:26:10Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/2632This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/26322017-11-16T04:26:10ZINVESTIGATION ON STRUCTURAL AND FERROELECTRIC PROPERTIES OF Bi3.25La0.75Ti3O12 THIN FILMSLanthanum doped bismuth titanate (Bi3.25La0.75Ti3O12 abbreviated as BLT) has been known
as one of typical materials for Bi-layered perovskite structure which possess several unique
properties such as good fatigue with metal electrode and stable remanent polarization, hence it
has potential applications in ferroelectric random access memory. In this work, the BLT thin
films were fabricated on Pt/TiO2/SiO2/Si substrates by using a solution process, and then their
features including crystal structure, surface morphology, and electrical properties were
characterized by using X-ray diffraction system (XRD), scanning electron microscopy (SEM),
and electrical measurement system (Radiant Precision LC 10), respectively. The obtained results
point out that the BLT thin film annealed at 725oC is mostly optimum from a viewpoint of film
quality and ferroelectricity. In particular, the optimum BLT thin film having a thickness of 200
nm does not contain any cracks on the sample surface, and the grain size is closed to 400 nm from
SEM observation. XRD patterns imply that the BLT thin film had stoichiometric structure with
preferred orientations of (117) and (006), when annealed at temperatures higher than 725oC. In
addition, we found the influence of La (0.75) dopping on c-axis-oriented growth of BLT thin
films is clear from the structural analysis. The remanent polarization of optimum BLT thin film is
approximately 10 µC/cm2, but the ferroelectric hysteresis loops are not saturated at low applied
voltages.Van Dung TranHa HoangThi Thanh Tam HoangThi Dung VuVan Dung NguyenHong Minh DoThi Huyen Trang VuQuang Hoa NguyenNguyen Quoc Trinh Buitrinhbnq@vnu.edu.vn2017-11-09T03:23:15Z2017-11-09T03:23:15Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/2626This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/26262017-11-09T03:23:15ZSolution-processed doping and undoping zinc-oxide and copper-oxide thin filmsZinc-oxide (ZnO) and copper-oxide (CuO) based thin films have attracted a huge attention owing to controllable electrical conductivity and low-cost materials for manufacturing electronic and photonic devices. In this work, we have characterized on physical properties of undoped and doped (ex.: Ag, Al) ZnO and CuO thin films, prepared by using a solution process. For formation of precursor solution, zinc/copper nitrate hexahydrate (original or doping), water and citric acid were used as metal salt, solvent and stabilizer, respectively. After that, using the precursors mixed, ZnO/CuO thin films were spin-coated on glass substrates followed by an annealing process below 550oC. Structural, morphological, optical and electrical properties of the thin films were, in turn, evaluated by using X-ray diffraction, scanning electronic microscopy, UV-vis, and four-probe measurement systems. Achievement results show that, when annealing temperatures increased from 450°C to 550°C, the thin films were oriented more preferentially along (100) (002) and (102) directions. ZnO based thin films were relatively porous, and whose band-gap energy was closed to 3.2 eV. In addition, characterization on CuO thin films will be discussed in this conference.Van Dung NguyenQuang Hoa NguyenVan Dung TranNguyen Quoc Trinh Buitrinhbnq@vnu.edu.vn