| Titre : | Study on the Structural, Optical and Electrical Properties of pure NiO and La-doped NiO, prepared by sol-gel method. |
| Auteurs : | Walid REGUIAI, Auteur ; Said Lakel, 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.(57p) / ill.couv.ill en coul |
| Langues: | Anglais |
| Langues originales: | Anglais |
| Mots-clés: | La doped NiO, metal oxide semiconductors (MOS), p-type transparent oxide thin films, sol–gel process, spin coating technique, XRD, physical properties, optoelectronic |
| Résumé : |
We report an experimental study focuses on the synthesis and characterization of thin films of nickel oxide undoped and doped with lanthanum (La) prepared by sol-gel spin coating technique on glass substrates annealed at temperature 500°C. The main objective is to provide a comprehensive study on the effect of the doping on the physical properties of this material. For that, we used Lanthanum (III) nitrate La (NO3)3 a as precursors, has a rate of doping was (3%, 6%, 9%). The structural, optical and electrical properties of the obtained films were characterized by various techniques. X-ray diffraction analysis of pure an La-doped NiO thin films exhibit that the final films belonging to cubic structure, crystallize preferentially along (111) plane. The crystallite size represents the variations from 26.7 nm to 5.5 nm. The optical analysis shows that NiO: La films present a direct band gap energy value lying in the range of 3.63-3.82 eV. Also, the effect of the La incorporation in NiO matrix on the disorder is studied in terms of urbach energy. Finally, it has been found that La doping allows the improvement of the electrical conductivity, where the measurements of the sheet resistance of samples confirm that this Rs is the order of 109 (Ω/square) for pure NiO films, and are about 106 (Ω/square) for doped films. |
| Sommaire : |
General introduction .............01 I.1 Transparent Conductive Oxides (TCOs) ..............05 I.1.1 Optical and Electrical Properties of TCOs .......07 I.1.2 TCOs material and their relevance to some applictions .........08 I.2 Nickel oxide (NiO) ..................09 I.2.1 Fundamental properties of NiO......09 I.2.1.1 Structural Properties ...........09 I.2.1.2 Optical Properties ..............10 I.2.1.3 Electrical Properties ...........10 I.2.1.4 Magnetics Properties ............11 I.3 Latest work and applications on nickel oxide thin films .....................12 I.3.1 Transparent Electrodes for Flexible Organic Photovoltaic Cells ............12 I.3.2 Thin Film Transistors (TFTs) .................13 I.3.3 Organic Light-Emitting Diodes (OLEDs) ........14 I.3.4 Electrochromic Devices (ECDs).................15 I.4 Nickel oxide (NiO) doping .......17 I.4.1 Lanthanum material ............17 I.4.2 Lanthanum-doped nickel oxide (NiO) .............18 I.5 Thin film concepts .............19 I.5.1 Mechanism of film formation ..19 I.5.2 Thin film growth process .....20 I.5.2.1 Nucleation .................20 I.5.2.1 Growth modes ...............21 I.5.3 Deposition techniques of thin films ..................22 I.5.4 Sol-gel based coating technics .......................23 I.5.4.1 Deep-coating ..........23 I.5.4.2 Spin-coating ..........24 II.1 Introduction .............27 II.2 Materials ................27 II.3 Elaboration of NiO thin films ..................28 II.3.1 Experimental montage of spin-coating system ..................28 II.3.2 Experimental procedure .........29 II.3.2.1 Preparation and cleaning procedure of glass substrates .....29 II.3.2.2 Preparation of coating solution ............................29 II.3.2.3 Thin film deposition parameters ............................30 II.3.2.4 Deposition process of the NiO thin films ...................31 II.4 Characterization methods .........................32 II.4.1 X-ray Diffraction XRD (Structural properties) ................32 II.4.2 UV-Vis Spectrophotometry (Optical properties) ................32 II.4.3 Four-point probes (Electrical properties) ....................32 III.1 Structural properties of Ni1-x LaxO thin films ................34 III.1.1 XRD analyses of Ni1-x LaxO samples ..........................34 III.2 Optical properties of Ni1-x LaxO thin films ...................38 III.2.1 Transmittance, absorbance and reflectance spectra of Ni1-x LaxO samples ........38 III.2.2 The optical band gap (Eg) of Ni1-x LaxO films ...............39 III.2.3 Urbach energy Eu (Disorder Eu) .......41 III.3 Electrical properties of Ni1-x LaxO thin films ................42 General Conclusion ..............44 |
| Type de document : | Mémoire master |
Disponibilité (1)
| Cote | Support | Localisation | Statut |
|---|---|---|---|
| MPHY/645 | Mémoire master | bibliothèque sciences exactes | Consultable |
