A facile and transfer-free path for template-less synthesis of carbon nanosheets

A facile and transfer-free path is demonstrated on the template-less synthesis of carbon nanosheets (CNSs). CNSs were synthesized by annealing amorphous carbon film with gallium (Ga) droplet catalyst. Liquid Ga was deposited on Si substrate by electron-beam evaporation. Carbon thin film was subsequently deposited on Ga droplets. Submicron-scale Ga droplets were generated from the non-wetting nature. The carbon films supported on Ga droplets were annealed in tube furnace at 1000 °C. After annealing, CNSs were synthesized on Si surface and their size and height distributions were also analyzed. Raman measurements demonstrate the graphitization of the amorphous carbon film, indicating Ga droplets as good graphitizing catalyst for CNSs. The proposed method provides a simple and transfer-free route to synthesize CNSs on Si substrates, which facilitates the subsequent processing of Si-based nanoelectronics products.