Formation and Characterization of 2D Metal Carbides for EM Shielding Applications: Experimental and First Principles Computational Study
Abstract:
Growth of Mo2C crystals was studied through chemical vapor deposition on copper substrates. The effects of impurities, Cu substrate thickness, and graphene presence on the morphology and crystal quality were investigated. Two growth regions were identified: directly on the copper surface and on graphene-covered areas. Mo2C crystals formed on graphene exhibited enhanced properties attributed to graphene's role as a diffusion barrier for Mo atoms. Additionally, the formation of a graphene/ Mo2C /graphene sandwich structure was observed, showing promise for electronic applications.An alternative approach to Mo2C crystal growth using liquid indium as a substrate was studied. The team demonstrated the suitability of In as an suitable substrate for the growth of Mo2C crystals through the CVD (Chemical Vapor Deposition) method.--An investigation into the growth mechanism of Mo2C crystals on In utilizing the CVD technique has been undertaken. The proposed model indicates an inversely proportional relationship between the vertical growth of Mo2C crystals and the thickness of the In substrate. This conceptual framework has been validated through AFM investigations.--Nucleation and Growth of Graphene/ Mo2C Heterostructures on Cu through CVD study has revealed that the thickness and morphology of Mo2C crystals exhibit variability based on their growth location on the Cu surface. This variation is attributed to the differing diffusion distances traveled by Mo species. The underlying pressure conditions play a pivotal role in influencing the nucleation and growth mechanisms not only for graphene but also for Mo2C.Besides the CVD studies, the team also performed studies on the formation of Mo2C flakes through wet etching of MAX Phase (Mo2CSnC), which in this case called MXenes. Mo2CTX, derived primarily from the Mo2Ga2C MAX phase, presents noteworthy theoretical electrochemical, thermoelectric properties, and chemical stability.