| Titre : | Effect of substrates on the properties of ZnO thin films elaborated with the sol-gel methode |
| Auteurs : | Ben khelifa Fouzia, Auteur ; Louiza Arab , Directeur de thèse |
| Type de document : | Monographie imprimée |
| Année de publication : | 2025 |
| Format : | 1 vol. (100 p.) |
| Langues: | Anglais |
| Langues originales: | Anglais |
| Mots-clés: | Zinc Oxide, Sol-gel, spin coating, Thin films, Substrates, X-ray diffraction, UV-Vis spectrometers, four-probe technique. |
| Résumé : |
In this experimental work, we prepared thin films of undoped Zinc Oxide at low
temperatures using the Sol-gel chemical method. Seven successive layers were deposited on different substrates including glass, silicon type-p, and indium tin oxide (ITO). The films deposited using the Spin-coating technique. We studied the influence of the different substrates on the structural, optical, and even electrical properties of the films. X-ray diffraction revealed that the films possess a polycrystalline structure with a hexagonal wurtzite phase. Optical property analysis using UV-Vis spectroscopy showed that glass substrates exhibited very high transparency compared to indium tin oxide (ITO) substrates. Additionally, the four-probe technique revealed good electrical conductivity for the silicon substrate, while the other substrates showed higher resistivity. |
| Sommaire : |
Dedication………………………………………………………………………………. I
Acknowledgements……………………………………………………………………... II Content table………………………………………………………………………….... III List of Tables…………………………………………………………………………… VII List of Figures………………………………………………………………………….. VIII General Introduction…………………………………………………………………... 1 Chapter I: Bibliographic Research I.1. Introduction………………………………………………………………………. 4 I.2. What is Transparent Conducting Oxide?………………………………………… 4 I.2.1. Some properties of TCOs……………………………………………………. 4 I.2.1.1. The electrical properties of TCO……………………………………....... 5 І.2.1.2. The optical properties of TCO………………………………………….. 5 І.2.1.2.a. The transmittance T…………………………………………………… 5 І.2.1.2.b. The reflection R……………………………………………………….. 5 І.2.1.2.c. The absorption factors A………………………………………………. 6 I.2.2. Different types of defects in transparent conductive oxides(TCOs)…………. 7 І.2.3. Transparent conductive oxide applications…………………………………... 8 I.3. The Zinc Oxide………………………………………………………………........ 9 I.3.1. History of zinc oxide "ZnO"…………………………………………………. 10 I.3.2. The choice of the studied semiconductor ZnO………………………………. 11 I.3.3. Properties of Zinc Oxide……………………………………………………... 11 I.3.3.1. Physical Properties…………………………………………………….... 12 I.3.3.1.1. Crystallographic properties………………………………………….... 12 I.3.3.1.2. electronic structure of a band……………………………………......... 14 I.3.3.1.3. Optical and luminous characteristics……………………………......... 16 I.3.3.1.4. .Mechanical properties………………………………………............... 17 I.3.3.1.5. The piezoelectric effect………………………………………….......... 18 I.3.3.1.6. Magnetic properties………………………………………………….... 18 IV content table I.3.3.2. Chemical Properties…………………………………………………...... 18 I.3.4. Applications of Zinc Oxide…………………………………………….......... 19 I.4. Nanotechnologies……………………………………………………………......... 20 I.4.1. Materials at the nanoscale……………………………………………………. 21 I.4.2. ZnO nanoparticles……………………………………………………………. 23 I.4.3. Morphology Controlled………………………………………………………. 23 I.4.4. Properties of Zinc Oxide Nanostructures…………………………………….. 24 I.4.4.1. Electronic properties of nanomaterials…………………………………. 24 I.4.4.2. Mechanical properties of nanomaterials………………………………... 25 I.4.4.3. Piezoelectric properties of nanomaterials…………………………......... 25 I.4.4.4. Optical properties of nanomaterials………………………………......... 25 I.5. Brief history……………………………………………………………………….. 26 I.5.1. What is a thin film?............................................................................................ 26 I.5.2. Applications of Zinc Oxide thin films………………………………………... 27 I.5.3. Technological challenges of thin films………………………………….......... 28 References……………………………………………………………………………… 30 Chapter II: Elaboration and characterization methods II .1. Introduction………………………………………………………………............. 36 II .2. Thin film Deposition Methods……………………………………………............ 36 II .3. Sol-gel method……………………………………………………………………. 37 II .3.1. History of the sol-gel method……………………………………………… 37 II .3.2. Definition of the sol-gel………………………………………………….... 38 II.3.3. The Sol-gel process………………………………………………………… 38 II.3.3.1. The sol-gel transition……………………………………………….. 39 II.3.3.2. Reaction mechanisms…………………………………………......... 40 II.3.3.2. a. Hydrolysis reaction…………………………………………......... 40 II.3.3.2 b. Condensation reaction…………………………………………..... 40 II.3.3.3. Gelation……………………………………………………….......... 41 II.3.3.4. Ageing…………………………………………………………….... 41 V content table II.3.3.5. Drying………………………………………………………............ 41 II.3.4. parameters influencing the reaction rate……………………………............ 42 II.3.5. Gel Drying…………………………………………………………………. 42 II.3.6. Sol-gel deposition techniques…………………………………………….... 43 II.3.6.1. Spin-coating………………………………………………………... 44 II.3.6.2. Dip-coating………………………………………………………… 46 II.3.7. Applications of the sol-gel method………………………………………... 46 II.3.8. Advantages of the sol-gel method……………………………………….... 47 II.3.9. Drawbacks of the sol-gel method……………………………………......... 47 II.4. Characterization techniques………………………………………………….......... 48 II.4.1. X-ray Diffraction………………………………………………………...... 48 II.4.1.a. Apparatus………………………………………………………........ 48 II.4.1.b. The X-ray diffraction measurement principle…………………........ 49 II.4.1.c. Determination of interatomic distances and lattice parameters........ 49 II.4.1.d. Determination of grain size and stresses…………………………... 50 II.4.2. Optical characterization…………………………………………………… 52 II.4.2.1. absorption spectra…………………………………………………... 55 II.4.2.2. Optical band gap ( |
Disponibilité (1)
| Cote | Support | Localisation | Statut |
|---|---|---|---|
| MPHY/661 | CDROM | bibliothèque sciences exactes | Consultable |
