Carbon nano tubes grown on glass substrate with different interface layer

Abstract

Microwave plasma enhanced chemical vapor deposition (MPECVD) was applied in growing carbon nano tubes (CNTs) on sodium free glass with different interface layer materials. Surface morphology and field emission characteristics of as grown CNTs were measured. Three different materials: titanium(Ti), gold(Au) and indium tin oxide (ITO) thin films were prepared on glass first as the interface role between CNTs and glass. Nickel(Ni) films were sputtered on three different interface films and also direct on glass. After hydrogen plasma pretreatment on nickel films, CNTs were tried to grow on four kinds of glass combination: Ni/glass, Ni/ITO/glass, Ni/Au/glass and Ni/Ti/glass, three substrate temperatures: unheated, 300°C and 500 °C, with the mixture of methane and hydrogen microwave plasma. It was found CNTs can be grown with high CNTs density, high adhesion and 2.5V/ µ m turn on electric field corresponding to Ni/Ti/glass and 500 °C process condition. The same MPECVD system with same pretreatment and process gas can be used to grow CNTs on silicon substrate without extra substrate heating. It is proposed the electrical conductivity of substrate has strong influence on CNTs growth. The interface material like Ti can modify the electrical conductivity of the substrate surface.