| Titre : | Preparation and characterization of ZnO- based Schottky diode prepared with sol-gel |
| Auteurs : | Chaima Chenni, Auteur ; Louiza Arab , Directeur de thèse |
| Editeur : | Biskra [Algérie] : Faculté des Sciences Exactes et des Sciences de la Nature et de la Vie, Université Mohamed Khider, 2024 |
| Format : | 1VOL.(89p) / ill.couv.ill.en coul / 30cm |
| Langues: | Anglais |
| Langues originales: | Anglais |
| Mots-clés: | Key words: Thin films, sol–gel, ZnO, junction diodes, metal–insulator–Semicond |
| Résumé : |
Preparation and Characterization of ZnO-based Schottky diode Prepared with Sol–Gel Method. A ZnO-based Schottky diode have been fabricate via the deposition of a ZnO film codoped with Al + In on a Gallium-doped ZnO film with sol–gel method. The XRD of the films shows a polycrystalline structure and grains size in nanoscale. The films present a high transmittance in the visible, and the I–V characteristics show a Schottky-type behavior in the dark and under light, which is controlled by the thickness of the resistive layer. and the optical properties will be analyzed with the UV-Vis spectrophotometer.
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| Sommaire : |
Dedication .................................................................................................................................. I Acknowledgements .................................................................................................................. II Table of Content ..................................................................................................................... III List of Tables ......................................................................................................................... VII List of Figures ...................................................................................................................... VIII General Introduction ........................................................................................................... XII Chapter I: Overview of Transparent Conductive Oxides (TCO): Zinc Oxide (ZnO). I.1.1. Introduction ............................................................................................................. 1 I.2. Transparent conductive Oxides (TCO) ....................................................................... 1 I.3. Definition of TCO ...................................................................................................... 1 I.4. Properties of TCO ....................................................................................................... 1 I.4.1. Optical Properties .................................................................................................... 1 I.4.1.1. Reflectance .................................................................................................. 1 I.4.1.2. Absorbance .................................................................................................. 2 I.4.1.3. Transmittance .............................................................................................. 2 I.4.1.4. Absorption coefficient ................................................................................. 2 I.4.1.5. Extinction coefficient .................................................................................. 2 I.4.1.6 . Merit coefficient .......................................................................................... 3 I.4.2. Electrical Properties ................................................................................................. 4 I.5. Criteria for Choosing TCO ......................................................................................... 4 I.6. Applications of TCOs materials ................................................................................. 5 I.7. Nanomaterials ............................................................................................................. 6 I.8. Classification of nanomaterials .................................................................................. 6 I.9. Thin films ................................................................................................................... 7 I.10. Thin films growth process ........................................................................................ 8 I.10.1. Growth modes ........................................................................................................ 8 I.11. Zinc oxide (ZnO) ...................................................................................................... 9 I.12. Why chose ZnO specifically? ................................................................................. 10 I.13. Properties of zinc oxide .......................................................................................... 11 I.13.1. Structural properties of ZnO ................................................................................ 12 I.13.2. Electrical and electronic properties ..................................................................... 15 I.13.3. Optical properties and luminescence ................................................................... 18 I.13.4. Review of doped zinc oxide thin films ................................................................ 19 I.14. Zinc oxide applications ........................................................................................... 20 I.14.1. Transparent conductive oxides ............................................................................ 20 I.14.2. Gas Sensors .......................................................................................................... 20 I.14.3. Light-Emitting Diodes ......................................................................................... 21 I.14.4. Photoconductor .................................................................................................... 22 I.14.5. Schottky Photodiode ............................................................................................ 23 I.14.6. pn Homojunction Diode ...................................................................................... 24 Chapter II: Thin films deposition methods and characterization techniques. II.1. Introduction ............................................................................................................. 26 II.2. Deposition methods of thin films ............................................................................ 26 II.3. Choice of a deposition technique ............................................................................ 26 II.4. Physical Processes ................................................................................................... 27 II.4.1. Physical Vapor Deposition (PVD) ........................................................................ 27 II.4.1.1. Different types of PVD ............................................................................ 27 II.4.1.2. Pulsed Laser Deposition (PLD) ............................................................... 27 II.4.1.3. II.4.1.3. PVD-Sputtering .......................................................................... 28 II.5. Chemical Processes ................................................................................................. 29 II.5.1. Chemical Vapor Deposition (CVD) ..................................................................... 29 II.5.2. Spray Pyrolysis ..................................................................................................... 30 II.5.3. Sol-Gel ................................................................................................................. 31 II.5.3.1. Principle of the Sol-Gel method .............................................................. 31 II.5.3.2. Sol-Gel synthesis ..................................................................................... 31 II.5.3.3. Reaction mechanisms in the Sol-Gel process .......................................... 32 II.5.3.4. Solution deposition processes .................................................................. 34 II.5.3.5. The advantages of the Sol-Gel technique ................................................ 35 II.5.3.6. disadvantages of the Sol-Gel technique ................................................... 35 II.6. Characterization Methods ....................................................................................... 36 II.6.1. Thickness Measurements ..................................................................................... 36 II.6.2. Interference fringe ................................................................................................ 36 II.6.3. Structural Characterization ................................................................................... 39 II.6.4. Mesh Parameters Determination .......................................................................... 41 II.6.5. Crystallite Size Determination ............................................................................. 42 II.6.6. Strain Determination ............................................................................................ 43 II.7. Optical Characterization .......................................................................................... 44 II.7.1. Spectroscopy UV-Visible ..................................................................................... 44 II.7.2. Transmittance Spectra .......................................................................................... 45 II.7.3. Optical Band Gap ................................................................................................. 45 II.7.4. Urbach Energy ...................................................................................................... 46 II.8. Electrical Characterization ...................................................................................... 47 II.8.1. Four-Points Probes Method .................................................................................. 47 II.8.2. Electrical Resistivity Measurement ...................................................................... 48 II.8.3. The IV measurement technique for diodes ........................................................... 49 Chapter III: Experimental part: elaboration, results and discussion. III.1. Introduction ............................................................................................................ 54 III.2. Used apparatus (Spin coater) ................................................................................. 54 III.3. Elaboration of ZnO Thin Films .............................................................................. 55 III.3.1. Choice of deposition substrate ............................................................................ 55 III.3.2. Cleaning of the substrates ................................................................................... 56 III.3.3. Deposition of Thin Film ...................................................................................... 56 III.4. Results and discussion ........................................................................................... 58 III.4.1. Adhesion test ....................................................................................................... 58 III.4.2. Structural Properties ............................................................................................ 58 III.4.2.1. X-ray Diffraction Spectrum (XRD) ........................................................ 58 III.4.2.2. Crystallite Size and Strain ...................................................................... 60 III.4.3. Optical properties ................................................................................................ 62 III.4.3.1 . Transmittance ......................................................................................... 62 III.4.3.2. Band Gap and Urbach Energy ................................................................ 65 III.4.4. Electrical Properties ............................................................................................ 68 III.4.4.1 . The four-point characteristics ................................................................. 68 III.4.4.2. The I–V characteristics ........................................................................... 70 REFERENCES ....................................................................................................................... 75 ANNEXES ............................................................................................................................... 84 Abstract ................................................................................................................................... 89 Résumé .................................................................................................................................... 89 |
| Type de document : | Mémoire master |
Disponibilité (1)
| Cote | Support | Localisation | Statut |
|---|---|---|---|
| MPHY/648 | Mémoire master | bibliothèque sciences exactes | Consultable |
