Synthesis and field emission properties of topological insulator Bi ₂Se ₃ nanoflake arrays

High quality Bi ₂Se ₃ nanoflake arrays with a large area and high-yield production have been fabricated by chemical vapor deposition. As the essential candidate for a topological insulator, the unique surface electronic states are considered to play a crucial role distinct from the bulk. Our experimental results show that environmental doping significantly affects the field emission properties of the synthesized Bi ₂Se ₃ nanoflake arrays. X-ray photoelectron spectroscopy characterizations indicate that the rapid surface oxidation may prohibit the detection of the topological surface state and results in a low field emission current. This work provides another insight to investigate the surface state of topological insulator materials.