| Titre : | The effect of bromine doping rate on the properties of ZnO thin films |
| Auteurs : | Brahimi Lakhdar, Auteur ; Nadjette Hamani, Directeur de thèse |
| Type de document : | Monographie imprimée |
| Editeur : | Biskra [Algérie] : Faculté des Sciences Exactes et des Sciences de la Nature et de la Vie, Université Mohamed Khider, 2023 |
| Format : | 1vol(54) |
| Langues: | Français |
| Mots-clés: | Thin films, ZnO, TCO, Pneumatic spray, DRX, Br , doping, Optical and electrical properties |
| Résumé : | In this work, we deposited thin films of unpoped and doped zinc oxide (ZnO) with bromine (Br) in different proportions (2%, 4%, 6%, 8%) on glass substrates by pneumatic spray pyrolysis. The characterization of the films was studied by X ray diffraction (XRD), visible UV spectroscopy and the four point method .the results XRD showed that all samples have a compact hexagonal structure of polycrystalline zinc oxide, with a preferential growth direction (002). In our work, we found that crystalite size increase in the ranges from 29.91 to 47.16 nm. The optical study showed that the transmittance increases with increasing the doping percentage, and its highest value was at the doping percentage of 6%, reaching 85%, In addition, The energy gap was also calculated, and we found that it increases with increasing doping percentage, ranging from 3.17 to 3.34ev, while the Urbach energy decreases with increasing doping. Electrical measurements indicated All films have a conductivity in the range from 1.6×10-3 to 6.8×10-3 (Ω. m)-1. |
| Sommaire : |
Acknowledgements….........II
Dedication ...............III List of figures...........VII List of tables............IX GENERAL INTRODUCTION.......1 Chapter I: Bibliographic studies of zinc oxide I.1.Transparent conductive oxides…………………………………………3 I.2 Zinc oxide ………………………………………………4 I.3 Properties of ZnO…………………………………4 I.3.1.The crystallographic properties…………………………………5 I.3.2. Electronic Structure of ZnO …………………………………6 I.3.3 Electrical properties………………………………………7 I.4.Doping of ZnO………………………………………………8 I.5 Applications of Zinc Oxide……………………8 I.6 Thin films preparation Techniques……………………………………10 I.6.1.Physical vapor deposition (PVD)………………………………10 I.6.1.1 Thermal evaporation by resistive heating……………………10 I.6.1.2.Electron beam evaporation…………………………………11 I.6.1.3.Sputtering………………………………………12 V I.6.1.4.Molecular Beam Epitaxial (MBE)…………………………………13 I.6.2.Chemical vapor deposition………………………13 References………………………………………15 Chapter II: Spray pyrolysis and characterization methods II.1.Spray pyrolysis………………………………17 II.2. Characterization methods………………………………18 II.2.1.Thickness measurement…………………………………18 II.2.1.1 Weight method……………………………………19 II.2.2.X-ray diffraction (XRD)………………………………………19 II.2.3.Scanning electron microscope SEM…………………………………22 II.2.4.Measurement of optical properties………………………………23 II.2.5 Electrical characterization techniques……………………………………………26 References……………………………………………27 Chapter III: Results and discussions III.1.Introduction………………………………………………………………………29 2.Experimental method………………………………………………………………29 III.2.1 Pneumatic spray pyrolysis technique…………………………………………29 III.2.2.Preparation of substrates and spray solutions…………………………………30 III.2.2.1.Preparation of substrates………………………………………30 III.2.2.2 Preparation of solutions…………………………………………31 VI III.2.2.3 Deposition of thin films……………………………………………32 III.3.Results and discussions…………………………………………………………33 III.3.1. Growth rate of the films ………………………………………………………33 III.3.2 Structural study………………………………………………………………34 III.3.3.Optical study …………………………………………………………………38 III.3.3.1.Band gap energy ………………………………………………………39 III.3.3.2.Urbach energy of Br-doped ZnO thin films……………………………41 III.3.4 Electrical study…………………………………………42 References………………………………………………………………………………44 General conclusion…………………………………………………………46 Abstract……………………………………………………………………………………47 |
Disponibilité (1)
| Cote | Support | Localisation | Statut |
|---|---|---|---|
| MPHY/637 | Mémoire master | bibliothèque sciences exactes | Consultable |
