| Titre : | Elaboration and characterization of SnO2 : in thin films deposited by spray pyrolysis technique |
| Auteurs : | Kheira Bennaceur, Auteur ; Abdallah Attaf, 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. (108 p.) / 30 cm |
| Langues: | Anglais |
| Résumé : |
In this work, we have used the ultrasonic spray technique to deposit thin films of undoped and doped SnO2 on glass substrates. To optimize the quality of SnO2 thin films, we have studied the influence of molarity, deposition time and substrate temperature on film’s physical properties. The other aim of this work is to optimize the quality of these films by studying the influence of the dopants, the annealing temperature and the type of precursor of the starting solution on the structural, optical and electrical properties in order to obtain transparent and conductive films. For this reason, we used indium as a dopant and two types of the precursor of the starting solution (SnCl2.2H2O, SnCl4.5H2O). We used several characterization techniques, such as X-ray diffraction, UV-visible spectroscopy, scanning electron microscopy, Hall Effect and the four-point technique. We have shown that undoped and doped SnO2 films are transparent in the visible range and their structure is of tetragonal type. In our work, we found that the undoped SnO2 film deposited at 450° C for 5 minutes of deposition at a concentration of 0.1 mol / l has good properties. Also, indium-doped SnO2 thin films with the best properties can be prepared using SnCl4 as a precursor and at the 2% and 20% doping rate. Also, Hall Effect measurement revealed that the undoped and doped films with 10% In had n-type electrical conductivity, and when it was at 20%, In-doped SnO2 thin films showed a p-type conductivity. The results showed that the process of annealing leads to the improvement of the crystallinity, the optical and electrical properties of SnO2.In films. |
| Sommaire : |
Acknowledgment .......................................................................................................................I Dedication................................................................................................................................. II General Introduction................................................................................................................1 CHAPTER I: SnO2: a review on material and deposition process I.1. Transparent conducting oxides ............................................................................................5 I.1.1. Tin dioxide (SnO2)..........................................................................................................5 I.1.1.1. Crystal structure......................................................................................................6 I.1.1.2. Electrical properties ................................................................................................6 I.1.1.3. Optical properties....................................................................................................7 I.1.2. Influence of the doping on the properties of tin dioxide.................................................7 I.1.2.1. Crystallographic modifications...............................................................................8 I.1.2.2. Modifications of the optical properties of SnO2 .....................................................9 I.1.2.3. Modifications of the electrical properties of SnO2 ...............................................10 I.1.3. Influence of post-deposition annealing.........................................................................10 I.1.4. Applications of SnO2 thin films ...................................................................................12 I.1.4.1. Lithium-Ion Batteries (LIBs) ................................................................................12 I.1.4.2. Gas Sensors...........................................................................................................13 I.1.4.3. Solar cells..............................................................................................................13 I.1.4.4. Low-Emissivity coatings ......................................................................................14 I.2. Thin film deposition methods ............................................................................................14 I.2.1 Physical Methods...........................................................................................................15 I.2.1.1.Vacuum Evaporation .............................................................................................15 I.2.1.2. Pulsed Laser Deposition (PLD) ............................................................................16 I.2.1.3. Sputtering Process.................................................................................................16 I.2.2.Chemical Processes........................................................................................................17 I.2.2.1.Laser-Induced Chemical Vapor Deposition (LCVD)............................................17 I.2.2.2. Spin coating ..........................................................................................................18 I.2.2.3.Dip coating.............................................................................................................18 I.2.2.4. Spray pyrolysis .....................................................................................................19 References ................................................................................................................................22 CHAPTER II: Preparation of SnO2 thin films and characterization techniques II.1.Deposition Process.............................................................................................................26 II.1.1 The used deposition system..........................................................................................26 II.1.2. Preparation of substrates..............................................................................................27 II.1.2.1. Choice of the substrate ........................................................................................27 II.1.2.2. Cleaning of the substrate .....................................................................................27 III.1.3. Preparation of the solution .........................................................................................28 II.1.4. Deposition of thin films...............................................................................................30 II.1.5. Properties of the used elements ...................................................................................30 II.2. Characterization methods .................................................................................................31 II.2.1. Structural Analysis ......................................................................................................31 II.2.1.1. X- Ray Diffraction (XRD) Technique.................................................................31 II.2.1.2. Scanning Electron Microscopy (SEM)................................................................34 II.2.1.3.Thickness Measurement Using Weight Difference Method ................................36 II.2.2.Optical Analysis ...........................................................................................................36 II.2.2.1. Absorption coefficient .........................................................................................37 II.2.2.2.Optical Gap...........................................................................................................37 II.2.2.3. Disorder calculation of the Urbach Energy.........................................................38 II.2.3. Electrical Analysis.......................................................................................................39 II.2.3.1. Four-point probe..................................................................................................39 II.2.4. Hall measurement ........................................................................................................40 References ................................................................................................................................43 CHAPTER III: Optimum conditions for SnO2 thin films preparation III.1. Effect of molarities ..........................................................................................................46 III.1.1. Thickness of the film..................................................................................................46 III.1.2. Structural properties ...................................................................................................47 III.1.3. Optical properties .......................................................................................................50 III.1.4. Electrical properties ...................................................................................................52 III.2. Effect of deposition time .................................................................................................53 III.2.1.Thickness of the film...................................................................................................53 III.2.2.Structural properties ....................................................................................................54 III.2.3.Optical properties ........................................................................................................57 III.2.4.Electrical properties ....................................................................................................59 III.3. Effect of substrate temperature........................................................................................60 III.3.1.Thickness of the film...................................................................................................60 III.3.2. Structural properties ...................................................................................................61 III.3.3.Optical properties ........................................................................................................63 III.3.4.Electrical properties ....................................................................................................65 Conclusion................................................................................................................................66 References ................................................................................................................................67 CHAPTER IV: Effect of indium doping on the properties of tin dioxide (SnO2) thin films IV.1. Influence of Indium doping on properties of SnO2 films: Study of low concentrations 70 IV.1.1.Thickness of the film ..................................................................................................70 IV.1.2. Structural and morphological properties....................................................................71 IV.1.3. Optical properties.......................................................................................................75 IV.1.4. Electrical properties ...................................................................................................77 IV.2. Effect of Indium doping on properties of SnO2 films: Study of high concentrations.....77 IV.2.1. Structural properties...................................................................................................78 IV.2.2. Optical properties.......................................................................................................81 IV.2.3. Electrical properties ...................................................................................................83 Conclusion................................................................................................................................84 References ................................................................................................................................85 CHAPTER V: Effect of precursor and annealing temperature on the properties of SnO2:In thin films V.1. Effect of precursor on the properties of SnO2:In thin films .............................................87 V.1.1. Structural properties ......................................................................................................87 V.1.2. Optical properties ..........................................................................................................91 V.1.3. Electrical properties.....................................................................................................94 V.2. Effect of annealing temperature on the properties of SnO2:In thin films.........................95 V.2.1. Structural properties ....................................................................................................95 V.2.2.Optical properties .........................................................................................................99 V.2.3.Electrical properties....................................................................................................102 Conclusion..............................................................................................................................103 References ..............................................................................................................................105 General conclusion and perspectives......................................................................................107 Abstracts................................................................................................................................ |
| En ligne : | http://thesis.univ-biskra.dz/4862/1/final.thesis.with.abstract.pdf |
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| Cote | Support | Localisation | Statut |
|---|---|---|---|
| TPHY/98 | Théses de doctorat | bibliothèque sciences exactes | Consultable |
