Growth Mechanism of 2D Mo2C on Cu via CVD

Abstract

This study investigatesthe growth of Mo2C crystalsvia chemical vapor deposition (CVD) in the presence of a carbon (H-2/CH4 gas)-containing environment. The study employsboth theoretical and experimental approaches to investigate the verticaland lateral (in-plane) growth of Mo2C crystals. A physico-mathematicalconsideration is applied to develop an analytical forward model, whichincorporates bulk diffusivities, surface diffusivities, and solubilitygradients for Mo2C crystal growth. Coupled nonlinear flowequations have been advanced for the Mo-, Cu-, Mo2C layerframework and effectively predicted the Mo2C crystal growthrate for both vertical and lateral directions. Forming the Mo2C crystal height and diameter was directly correlated withcopper layer thickness and time using the forward model and then validatedby the experiments together with SEM and AFM studies. Studies showedthat the Cu layer thickness plays a crucial role in controlling theheight of the Mo2C crystal while it is not that criticalin changing the lateral dimension of the crystal. Beyond simply enhancingMo(2)C crystal growth and property-processing relationship,this study demonstrated the synthesis of designer Mo2C,which can be tailored to the needs of specific applications. Thisforward model will enable us to further enhance and exploit the familyof analogs of materials previously demonstrated by other methods. This study explores 2D Mo2C crystal growth usingCVD. The research combines theoretical and experimental methods toinvestigate both vertical and lateral growth. A physico-mathematicalmodel is developed, incorporating diffusivities and solubility gradients.Nonlinear flow equations predict Mo2C growth rates in differentdirections, validated through experiments and microscopy studies.The study highlights the influence of copper layer thickness on thecrystal height and demonstrates the synthesis of customizable Mo2C materials for specific applications.