Download or read book Novel Synthesis and Fabrication of ZnO Thin Films Via an Anhydrous Sol gel Route written by Lee Huat Kelly Koh and published by . This book was released on 2008 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, the aim to synthesise nano-sized zinc oxide particles in the form of thin films by using a novel anhydrous sol-gel technique was proposed, developed and demonstrated. The sol-gel was prepared using anhydrous zinc acetate [Zn(C2H3O2)2], monoethanolamine [H2NC2H4OH ] and isopropanol. The zinc oxide thin films were fabricated on soda-lime and fused silica substrates from both single- and multi- step spin-coating depositions. A range of widely reported zinc acetate concentrations, annealing temperatures and spin-coating speeds was chosen to characterise and study the various effects that these parameters have on the crystallographical, morphological, optical, electronic and electrical properties. The mean crystallite sizes and other structural properties (such as micro-strain and degree of crystallinity) were estimated using x-ray diffraction analysis. In combination with scanning electron microscopy, the increase in particle size was observed to be non-linear, changing from that of individual growth to that of particle conglomeration at higher precursor concentration and annealing temperature. Strong crystalline orientation along the (002) c-axis crystalline plane (with intensity ratio _ (002) value up to 0.95) was exhibited for films fabricated from low precursor concentrations, multi-layered and furnace pre-heated films. Optical transmittance and electronic bandgap was measured and calculated using UV-visible spectroscopy. Thin films with high transparency (> 98 % (T) after substrate subtraction) were achieved for films prepared from low precursor concentrations, while absorption wavelength and optical bandgap energy were consistent and in good agreement with recognised values of zinc oxide. Reproducibility and reliability tests carried out on the films show high morphological consistency and stability against temperature fluctuation, moisture and electrochemical effects. Surface morphologically, the films were dense. The electrical resistivity of the (single- and multi- layer) films, before and after forming gas treatment was also measured. The minimum resistivity value of all the single-layer films was calculated to be 9.58 x 102 _cm, and the electrical resistivity showed an overall mprovement (up to one order of magnitude). On contrary, the multi-layered films, which are more resistive, worsened in resistivity after forming gas treatment.
Download or read book Synthesis and Characterization of Sol gel Dip coated Al ZnO Thin Films written by Basim Abdullah AL-Farsi and published by . This book was released on 2017 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sol Gel Spin Coating Growth Of Gallium Nitride Thin Films A Simple Safe and Cheap Approach Penerbit USM written by Fong Chee Yong and published by Penerbit USM. This book was released on 2019 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wide direct band gap gallium nitride (GaN) semiconductor has received significant attention as an ideal material for various applications in the optoelectronic devices. One major use of GaN is the development of energy-efficient solid state light-emitting diodes. Currently, most commercially available GaN semiconductor are produced through advanced deposition techniques which involve sophisticated technologies and are relatively expensive and complicated to setup. As an alternative, the sol-gel spin coating method, which is relatively simpler, cheaper, safer, and more scalable was proposed. In this book, the process route and recipe for producing highly c-oriented crystalline GaN thin films via the sol-gel spin coating approach were described in detail. Some insights into the factors affecting the surface morphology as well as structural and optical properties of the deposited films were presented. Eventually, this book could inspire further studies into the development of low-cost GaN thin films.
Download or read book Synthesis of Zinc Oxide by Sol Gel Method for Photoelectrochemical Cells written by Siti Salwa Alias and published by Springer Science & Business Media. This book was released on 2013-11-20 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the study of synthesized ZnO powder using Zn(CH3COO)2∙2H2O precursor, methanol (as solvent), and sodium hydroxide (NaOH) to vary the pH. The successfully synthesized ZnO powder from the sol-gel centrifugation and sol-gel storage methods were characterized and investigated by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, UV–visible spectroscopy, and photoluminescence test to compare the properties of the nanoparticles. The best characteristic of the ZnO powder from both methods was observed when the powders were coated on an ITO glass to fabricate a PEC. The current density–voltage performances of both PECs were investigated under luminescent and dark conditions.
Download or read book Synthesis and Characterization of ZnO Graphene Nanostructures for Electronics and Photocatalysis written by Seyed Ebrahim Chalangar and published by Linköping University Electronic Press. This book was released on 2021-04-08 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent rapid development of electronics and electro-optical devices demands affordable and reliable materials with enhanced performance. Forming nanocomposites of already well-known materials is one possible route towards novel functional materials with desirable synergistic enhanced properties. Incompatible chemical properties, mismatched crystal structures and weak bonding interactions between the substances, however, often limit the number of possible nanocomposites. Moreover, using an inexpensive, facile, large-area and flexible fabrication technique is crucial to employ the new composites in industrially viable applications. This thesis focuses on the synthesis and characterization of different zinc oxide/graphene (ZnO/GR) nanocomposites, well suited for optoelectronics and photocatalysis applications. Two different approaches of i) substrate-free random synthesis, and ii) template-assisted selective area synthesis were studied in detail. In the first approach, ZnO nanoparticles/rods were grown on GR. The obtained nanocomposites were investigated for better GR dispersity, electrical conductivity and optical properties. Besides, by adding silver iodide to the nanocomposite, an enhanced plasmonic solar-driven photocatalyst was synthesized and analyzed. In the second approach, arrays of single, vertically aligned ZnO nanorods were synthesized using a colloidal lithography-patterned sol-gel ZnO seed layer. Our demonstrated nanofabrication technique with simple, substrate independent, and large wafer-scale area compatibility improved the alignment and surface density of ZnO nanorods over large selective growth areas. Eventually, we found a novel method to further enhance the vertical alignment of the ZnO nanorods by introducing a GR buffer layer between the Si substrate and the ZnO seed layer, together with the mentioned patterning technique. The synthesized nanocomposites were analyzed using a large variety of experimental techniques including electron microscopy, photoelectron spectroscopy, x-ray diffraction, photoluminescence and cathodoluminescence spectroscopy for in-depth studies of their morphology, chemical and optical properties. Our findings show that the designed ZnO/GR nanocomposites with vertically aligned ZnO nanorods of high crystalline quality, synthesized with the developed low-cost nanofabrication technique, can lead to novel devices offering higher performance at a significantly lower fabrication cost.
Download or read book Synthesis of Conductive Sol Gel ZnO Films and Development of ZnO Printed Electronics written by Farida Selim and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: ZnO thin films are synthesized and studied to understand the functionality of solution-processed semiconductor devices. A simple sol-gel technique is used to fabricate transparent conductive oxides (TCOs) and ultraviolet (UV) photodetectors from ZnO precursors via spin coating, inkjet printing (IJP), and aerosol jet printing (AJP). A variety of flexible and transparent substrates was selected based on the deposition and sintering conditions and the device application. Doping of ZnO films with Al3+, In3+, and Ga3+ was introduced in precursor solutions before deposition processes. Post-deposition processing was carried out in air, H2, and Zn environments to optimize thin film properties. Optical, structural, and electronic data analyses reveal the significant effects that deposition method, substrates, dopants, and processing conditions have on the optical transmission, crystallinity, grain size, and electrical conductivity.
Download or read book SYNTHESIS AND CHARACTERIZATION OF TRANSPARENT CONDUCTIVE ZINC OXIDE THIN FILMS BY SOL GEL SPIN COATING METHOD written by David Winarski and published by . This book was released on 2015 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc oxide has been given much attention recently as it is promising for various semiconductor device applications. ZnO has a direct band gap of 3.3 eV, high exciton binding energy of 60 meV and can exist in various bulk powder and thin film forms for different applications. ZnO is naturally n-type with various structural defects, which sparks further investigation into the material properties. Although there are many potential applications for this ZnO, an overall lack of understand and control of intrinsic defects has proven difficult to obtain consistent, repeatable results. This work studies both synthesis and characterization of zinc oxide in an effort to produce high quality transparent conductive oxides. The sol-gel spin coating method was used to obtain highly transparent ZnO thin films with high UV absorbance. This research develops a new more consistent method for synthesis of these thin films, providing insight for maintaining quality control for each step in the procedure. A sol-gel spin coating technique is optimized, yielding highly transparent polycrystalline ZnO thin films with tunable electrical properties. Annealing treatment in hydrogen and zinc atmospheres is researched in an effort to increase electrical conductivity and better understand intrinsic properties of the material. These treatment have shown significant effects on the properties of ZnO. Characterization of doped and undoped ZnO synthesized by the sol-gel spin coating method was carried out using scanning electron microscopy, UV-Visible range absorbance, X-ray diffraction, and the Hall Effect. Treatment in hydrogen shows an overall decrease in the number of crystal phases and visible absorbance while zinc seems to have the opposite effect. The Hall Effect has shown that both annealing environments increase the n-type conductivity, yielding a ZnO thin film with a carrier concentration as high as 3.001 × 1021 cm-3.
Download or read book Optimization of the Process for Sol gel Derived ZnO written by Matthew Nagorski and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Transparent and conducting Al-doped ZnO thin films with c-axis-preferred orientation were prepared on glass substrate via sol-gel route. The physical, optical and electrical properties were investigated to determine an optimal withdrawal speed, aluminum source and treatment in order to obtain a smooth, dense, highly crystalline, conductive and transparent thin film with a high figure of merit for transparent conducting oxide applications. An optimal withdrawal speed was found to be 2.5 cm/min. Optimal aluminum source and concentration was found to be 0.5 at.% using aluminum chloride hexahydrate. An additional treatment in an N2 environment was found to be the best method to improve the electrical properties of the films while maintaining high crystallinity and transparency.
Download or read book Multifunctional Oxide Based Materials From Synthesis to Application written by Teofil Jesionowski and published by MDPI. This book was released on 2019-09-03 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book deals with novel aspects and perspectives in metal oxide and hybrid material fabrication. The contributions are mainly focused on the search for a new group of advanced materials with designed physicochemical properties, especially an expanded porous structure and defined surface activity. The proposed technological procedures result in an enhanced activity of the synthesized hybrid materials, which is of great importance when considering their potential fields of application. The use of such materials in different technological disciplines, including aspects associated with environmental protection, allows for the verification of the proposed synthesis method. Thus, it can be stated that those aspects are of interdisciplinary character and may be located at the interface of three scientific disciplines—chemistry, materials science, and engineering—as well as environmental protection. Furthermore, the presented scientific scope is in some way an answer to the continuous demand for such types of materials and opens new perspectives for their practical use
Download or read book The Study of Sol gel Synthesized ZnO and IZO Thin Films and Its Applied in UV Photodetectors written by 徐榮彰 and published by . This book was released on 2009 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sol Gel Derived Optical and Photonic Materials written by Rui Almeida and published by Woodhead Publishing. This book was released on 2020-12-14 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sol-gel processing is a low temperature, low cost wet chemistry route to a range of different materials, particularly glassy and ceramic oxides, including nanoparticles and powders, fibers, thin films and membranes, or monoliths and composites. Thin films and coatings represent by far the most important category of sol-gel derived products with optical, electronic and magnetic functionalities, for example photoresist and dielectric spin-on-glass layers, flat screen displays, anti-reflection, conducting and magnetic disk coatings, as well as photochromic, electrochromic and photovoltaic coatings. Sol-gel derived materials are homogeneous at the molecular level and are a good example of a bottom-up approach to materials synthesis. There is increasing need of new optical and photonic materials with improved performance, where molecular level homogeneity and easy fabrication in film form may be especially convenient, highlighting a decisive advantage of sol-gel over other more established technologies to obtain graded index optical components, solar control coatings, phosphors, glass ceramics or multilayer photonic structures. There is no book available yet which focuses in particular on optical and photonic sol-gel derived materials. This is what makes this book unique at this point for those especially or exclusively interested in optical and photonic functional materials and applications. This book represents an important tool to update scientists and engineers with recent advances in the rapidly evolving field of optical and photonic materials, components and devices. Our target audience are those working in materials science, physics, engineering and chemistry disciplines, in particular academics and researchers working in advanced optical/photonic processing technologies, research and development engineers in high technology industries and research project leaders. This book will also be an essential tool for graduate students pursuing a PhD or even a Master's degree. Reviews wide range of sol-gel derived coatings including reflective and anti-reflective, self-cleaning, and electrochromic Discusses latest advances in sol-gel derived photonic crystals including one dimensional, two dimensional, and three dimensional structures Addresses key applications in solid state lighting, solar cells, sensors, fiber optics, and magneto-optical devices
Download or read book Fabrication of ZnO Thin Film Through Chemical Preparations written by Ersan Y. Muslih and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc oxide (ZnO) is a compound that has unique physical and chemical properties. It has a direct band gap at 3.4 eV (without dopant), a high bonding energy (60 meV), and a high thermal and mechanical stability at room temperature. Thus, ZnO thin film can be suitably applied in many fields, and it also has many functions such as UV light emitters, hydrophobic coating, transparent thin film in electronic devices, piezoelectric material, transducers, gas-sensing, and a transparent conductive oxide (TCO) layer in thin film solar cells. ZnO thin film could be prepared by many chemical preparations such as chemical bat deposition (CBD), chemical vapor deposition (CVD), sol-gel spin coating, doctor blade, printing deposition, and electrochemical deposition (ED). This chemical process is a low-cost, simple, and easy preparation process to be adjusted or doped by other elements.
Download or read book Synthesis of Zinc Oxide by Sol Gel Method for Photoelectrochemical Cells written by Siti Salwa Alias and published by . This book was released on 2013-11-30 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sol gel Synthesis of Nano bimetallic Oxide Thin Films written by Tich Lam Nguyen and published by . This book was released on 2005 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of ZnO Coated Activated Carbon Aerogel by Simple Sol Gel Route written by and published by . This book was released on 2010 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Aspects of Sol gel Routes to Pzt Thin Films written by Nimit Sriprang and published by . This book was released on 1998 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sol gel Synthesis of Nanocomposite Inorganic Systems written by Silvia Gross and published by . This book was released on 2000 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt:
