| Titre : | Preparation and characterization of Titanium dioxide and Zinc oxide thin films via Sol-Gel (spin coating) technique for optoelectronic applications |
| Auteurs : | Mohamed Dahnoun, Auteur ; Abdallah Attaf, Directeur de thèse ; Hanane Saidi, Directeur de thèse |
| Type de document : | Thése doctorat |
| Editeur : | Biskra [Algérie] : Faculté des Sciences Exactes et des Sciences de la Nature et de la Vie, Université Mohamed Khider, 2020 |
| Format : | 1 vol. (117 p.) / 30 cm |
| Langues: | Anglais |
| Mots-clés: | Couches minces,Sol-Gel revêtement par rotation,Dioxyde de Titane,Oxyde de Zinc,propriétés optiques,propriétés électriques,applications optoélectroniques |
| Résumé : |
In the present work we used Sol-Gel spin coating technique to deposit Titanium dioxide and Zinc oxide thin films. Our main goal is the production of films with suitable optoelectronic properties required for application as front transparent electrodes. In the first part we have prepared and characterized Titanium dioxide by varying the deposition parameters such as: the nature of stabilizer, annealing temperature, molar concentration and Zn doping, this last is accomplished with the goal to enhance the electrical properties. In the second part of this work we have deposited and studied the influence of the nature of stabilizer, annealing temperature and Ga doping on the properties of ZnO thin films. The structural, optical and electrical properties were investigated through: X-ray diffraction, Fourier transform-infrared, Photoluminescence, Raman spectroscopy, UV-visible spectroscopy, Scanning electron microscopy and Four-point probe method. |
| Sommaire : |
Preface i Chapter I: A Survey on TiO2, ZnO and their applications 1 I. 1. Introduction . 2 I. 2. What is transparent conducting Oxide? 3 I. 3. Titanium dioxide 4 I. 3. 1. TiO2 structural properties 4 I. 3. 2. TiO2 optical properties 6 I. 3. 3. TiO2 electrical properties 6 I. 4. TiO2 applications 7 I. 4. 1. Photocatalyst 7 I. 4. 2. Dye Sensitized Solar Cells 9 I. 5. Zinc oxide presentation 10 I. 5. 1. ZnO structural properties 10 I. 5. 2. ZnO electrical properties 11 I. 5. 3. Optical properties and luminescence 12 I. 6. Applications of Zinc Oxide thin films 13 I. 6. 1. ZnO as gas sensor 13 I. 6. 2. ZnO for Photocatalytic activity 15 I. 6. 3. ZnO as transparent electrodes for solar cells 15 Chapter II : Thin films deposition techniques and characterization tools 19 II. 1. Introduction 20 II. 2. What is a thin film? 21 II. 3. Thin films preparation Techniques 21 II. 3. 1. Physical vapor deposition (PVD) 22 II. 3. 1. 1. Thermal evaporation by resistive heating 22 II. 3. 1. 2. Electron beam evaporation 23 II. 3. 1. 3. Sputtering 24 II. 3. 1. 4. Pulsed laser deposition (PLD) 25 II. 3. 1. 5. Molecular Beam Epitaxy (MBE) 26 II. 3. 2. Chemical vapor deposition 27 II. 3. 3. Spray Pyrolysis technique 29 II. 4. Characterization tools of thin films 30 II. 4. 1. Structural characterization with X-ray diffraction 30 II. 4. 1. 1. Determination of the grains size 31 II. 4. 1. 2. Determination of the interreticular distances and the cell parameters 31 II. 4. 2. Scanning Electron Microscope (SEM) 32 II. 4. 3. Fourier Transform Infrared (FTIR) and Raman spectroscopy 34 II. 4. 4. Photoluminescence spectroscopy 34 II. 4. 5. Electrical characterization with four-point probe method35 II. 4. 6. Optical measures through spectroscopy (UV-VIS) 3 II. 4. 6. 1. The thickness of the film d (Swanepoel method): 37 II. 4. 6. 2. Absorption coefficient alpha II. 4. 6. 3. Optical Gap EG Chapter III : TiO2 and ZnO thin films deposition 41 III. 1. Sol-Gel method 42 III. 1. 1. An overview of sol-gel process steps 43 III. 1. 1. 1. Hydrolysis and condensation 43 III. 1. 1. 2. Gelation 45 III. 1. 1. 3. Ageing 46 III. 1. 1. 4. Drying46 III. 1. 1. 5. Densification 46 III. 1. 2. Different sol-gel methods 47 III. 1. 2. 1. Spin-coating 47 III. 1. 2. 2. Dip-coating: 48 III. 1. 3. Advantages and disadvantages of sol-gel method 49 III. 1. 3. 1. The advantages 49 III. 1. 3. 2. The disadvantages 49 III. 2. Apparatus used (Spin coater) 50 III. 2. 1. How does a spin coater work? 50 III. 2. 2. Specifications 50 III. 3. Preparation of the substrate 51 III. 3. 1. Choice of the substrate 51 III. 3. 2. Cleaning of the substrate 51 III. 4. Solutions preparation and films deposition 52 III. 4. 1. Titanium dioxide 52 III. 4. 2. Zinc oxide 53 References.................. 55 Chapter IV: TiO2 thin films characterisation (results and discussion) 56 IV. 1. Introduction 57 IV. 2. Nature of stabilizer effect on TiO2 thin films properties 58 IV. 2. 1. Adhesion test 59 IV. 2. 2. Structural study 60 IV. 2. 3. Raman spectroscopy 60 IV. 2. 4. Optical study 61 IV. 2. 5. Photoluminescence studies 63 IV. 3. Effect of annealing temperature 64 IV. 3. 1. Thickness variations 64 IV. 3. 2. Structural characterization 65 IV. 3. 3. Fourier transform-infrared (FTIR) 68 IV. 3. 4. Optical characterization 68 IV. 3. 5. Photoluminescence 71 IV. 4. Molar concentration effect 72 IV. 4. 1. Thickness variations 72 IV. 4. 2. Structural characteristics 72 IV. 4. 3. Optical study 75 IV. 4. 4. Photoluminescence 77 IV. 5. Effect of ZN doping 79 IV. 5. 1. Structural characteristics 79 IV. 5. 2. Optical properties81 IV. 5. 3. Electrical conductivity 82 References 83 Chapter V: ZnO thin films characterisation (results and discussion) 87 V. 1. Introduction 88 V. 2. Stabilizer effect on the properties of Zinc Oxide thin films 89 V. 2. 1. Structural study 89 V. 2. 2. Fourier transform-infrared (FTIR) 91 V. 2. 3. Optical study 91 V. 2. 4. Photoluminescence studies 93 V. 3. Effect of annealing temperature on ZnO properties 95 V. 3. 1. Structural characteristics 95 V. 3. 2. Optical studies 98 V. 3. 3. Films’ thickness 98 V. 3. 4. Optical band gap and Disorder (Urbach energy) 99 V. 3. 5. Electrical conductivity 100 V. 4. Ga-doped ZnO 101 V. 4. 1. Thickness of the films 101 V. 4. 2. Structural charachteristics 101 V. 4. 3. Optical study 104 V. 4. 4. Electrical properties 105 References................ 106 General conclusion and perspectives 109 Annexes111 Abstracts. |
| En ligne : | http://thesis.univ-biskra.dz/4860/1/PhD%20thesis.pdf |
Disponibilité (1)
| Cote | Support | Localisation | Statut |
|---|---|---|---|
| TPHY/97 | Théses de doctorat | bibliothèque sciences exactes | Consultable |
