Growth of Homogeneous High‐Density Horizontal SWNT Arrays on Sapphire through a Magnesium‐Assisted Catalyst Anchoring Strategy

Abstract In‐situ growth of high‐density single‐walled carbon nanotube (SWNT) arrays with homogeneity is highly desirable for integrated circuits. However, disastrous migration and aggregation of catalyst nanoparticles on substrate has greatly limited the area of as‐grown SWNT arrays. Herein, we develop a magnesium‐assisted catalyst anchoring strategy to restrain catalyst nanoparticles sintering on substrate. Magnesium modification ameliorates sapphire surface by high temperature solid reaction and thus provides a stronger metal‐support interaction (SMSI). Hereby, we realize the direct growth of high‐density SWNT arrays that fully cover an entire 10×10 mm 2 substrate with the local highest density of ≈110 tubes μm −1 using iron as catalyst. This strategy was also proven universal when employing solid carbide catalysts.