Nanoscale topological insulator materials have a large surface-to-volume ratio that can manifest the conductive surface states and are promising candidates for devices.[1] As a single Dirac-cone topological insulator with a large bulk gap,the layered bismuth telluride (Bi2Te3) which coupled by weak van der Waals interaction between adjacent quintuple layers,can be either exfoliated by mechanical exfoliation[2] and sonication[3],or intercalated by lithium cations between the layers[4].