Advances In the synthesis of high-quality graphene by hot-filament chemical vapor deposition techniques and its applications.

Abstract

Graphene, a single layer of carbon atoms arranged in hexagonal lattice, has been the object of study of many research groups, due to its astonishing theoretical properties such as high electrical conductivity, mechanical strength, transparency, chemical inertness and thermal conductivity. This doctoral thesis contributes to the advancement of understanding graphene growth on different substrates, without the assisting of Cu deposition using time consuming and very expensive techniques, such as sputtering deposition. It has been fabricated some gold and silver electrodes on insulating substrates and graphene have been transferred on top. Its electrical and spectroscopic characterization have been performed.<br /> <br /> The high-quality graphene obtained by Hot Filament Chemical Vapor Deposition on Cu, quartz and Pt substrate, has been tested on several applications such as ECG, SERS and gas sensing applications. The research begins with a comprehensive review of graphene properties and its significance in modern technology. Subsequently, it goes through into the fundamentals of CVD processes, highlighting the advantages and limitations of different CVD systems.<br /> <br /> The synthesis of graphene on various metallic substrates, particularly platinum, is thoroughly examined, to identify the optimal conditions for producing high-quality graphene with minimal defects. Characterization techniques such as Raman Spectroscopy, Atomic Force Microscopy (AFM), and Scanning Electron Microscopy (SEM) are employed to analyze the synthesized graphene. The results emphasize the considerable potential of graphene in various applications, point out the importance of substrate choice and the process parameters in achieving high-quality graphene.