Toward Exploring the Structure of Monolayer to Few-layer TaS₂ by Efficient Ultrasound-free Exfoliation

Tantalum disulfide nanosheets have attracted great interest due to its electronic properties and device applications. Traditional solution-ased ultrasonic process is limited by ultrasound which may cause the disintegration into submicron-sized flake. Here, an efficient multi-step intercalation and ultrasound-free process has been successfully used to exfoliate 1T-TaS₂. The obtained TaS₂ nanosheets reveal an average thickness of 3 nm and several micrometers in size. The formation of few-layer TaS₂ nanosheets as well as monolayer TaS₂ sheets is further confirmed by atomic force microscopy images. The few-layer TaS₂ nanosheets remain the 1T structure, whereas monolayer TaS₂ sheets show lattice distortion and may adopt the 1H-like structure with trigonal prism coordination.