Défense de thèse de doctorat en Sciences physiques - Ayrton SIERRA CASTILLO

Synthesis and Characterization of Vertically Aligned Metal Dichalcogenides Nanosheets for Gas Sensing

Jury

• Prof. Carmela APRILE (Unité de recherche en Chimie des Matériaux, UNamur), présidente
• Prof. Jean-François COLOMER (Unité de recherche en Physique du Solide, UNamur), secrétaire
• Prof. Marc DEBLIQUY (Service de Science des Matériaux, Université de Mons)
• Prof. Eduard LLOBET (Departament d’Enginyeria Electronica, Universitat Rovira i Virgili)
• Prof. Luc HENRARD (Unité de recherche en Physique du Solide, UNamur)
• Prof. Carla BITTENCOURT (Laboratoire de Chimie des interactions Plasma-surface, Université de Mons)
  

Abstract

Following the isolation of graphene in 2004, scientists quickly showed that it possesses remarkable properties. However, as the scientific understanding of graphene matured, it became clear that it also has limitations: for example, graphene does not have a bandgap, making it poorly suited for use in digital logic. This motivated exploration of monolayer materials “beyond graphene”, which could embody functionalities that graphene lacks. In recent years there has been an increased interest in layered materials such as semiconducting Metal Dichalcogenides (MDs). When isolated in their monolayer form, they are essentially a 2D material, with unique properties. The implementation of 2D materials into future electronic devices could be desirable for industry; as their potential applications include cheap, fast and flexible electronic devices. Furthermore, to fully exploit the unique electrical properties of these materials, such as high electron mobility, new synthesis, manipulation, integration and characterization techniques must be developed.

In this thesis, the synthesis of high quality and crystallinity vertical aligned multilayer MDs by the Chemical Vapor Deposition (CVD) technique is reported. The morphology and the structure, as well as the optical properties, of the so-produced material have been studied using electron microscopies (SEM and TEM), X-ray photoelectron spectroscopy (XPS), Photoluminescence (PL), UV–visible and Raman spectroscopies and X-ray diffraction (XRD). The so-synthesized materials are potentially interesting in various applications where edge accessibility or directionality of the nanosheets play a major role such as gas sensing. For that, the performance of these materials as a gas sensor to detect toxic gases, for example NO₂ and NH₃, were investigated and discussed in this thesis work.

Lien

https://teams.microsoft.com/l/meetup-join/19%3ameeting_NjJkMWE4YjktODUzMi00YmI5LWI3YjMtNWIzZDFkYzFjOGM0%40thread.v2/0?context=%7b%22Tid%22%3a%225f31c5b4-f2e8-4772-8dd6-f268037b1eca%22%2c%22Oid%22%3a%22d43fcafe-fad5-4471-a7a4-aafaf6425815%22%7d

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