Self-scrolling MoS2 metallic wires

Abstract

Two-dimensional (2D) van der Waals (vdW) materials with strong in-plane chemical bonds and weak interaction in the out-of-plane direction have been acknowledged as a basic building block for designing dimensional materials in 0D, 1D, 2D and 3D forms. Compared to the explosive research on 2D vdW materials, quasi-one-dimensional (quasi-1D) vdW materials have received rare attention, despite the fact that they also present rich physics in electronics and engineering implications. Herein, quasi-1D MoS₂ nanoscrolls are directly fabricated from CVD-grown 2D triangular MoS₂ sheets. The formation, stability and electronic properties of quasi-1D MoS₂ nanoscrolls are studied experimentally and theoretically. The formation of a nanoscroll always starts from the edge of a triangular MoS₂ sheet along its armchair orientation. The electronic properties of MoS₂ nanoscrolls are systemically studied with optical spectroscopy and electrical transport together with density-functional theory (DFT) calculations. Surprisingly, the carrier mobility and contact properties of MoS₂ nanoscroll based field effect transistors (FETs) are distinct from that of 2D MoS₂ sheets. The transition from a 2D semiconductor MoS₂ sheet to a 1D metallic MoS₂ nanoscroll is successfully achieved. It is expected that this method of fabricating MoS₂ nanoscrolls will attract wide interest for 1D transition metal dichalcogenides with novel physical and chemical properties.