INTERFACE ENGINEERING OF 2D MATERIAL NANODEVICES

Abstract

Attributing to the large surface-to-volume ration of 2D materials, their electrical performance is highly sensitive to extrinsic factors arising from surface and interface in the device configuration. In this thesis, by adopting crested substrates, high-performance transition metal dichalcogenides (TMDCs) based field effect transistors (FET) have been successfully achieved at room temperature, with two order of magnitude improvement in field effect mobility. An enhanced spin relaxation has been observed at low temperature in crested MoS2 based FETs with standard bottom-gate geometry. Apart from the 2D interface between substrate and material, TMDCs based heterostructures with 1D seamless interface synthesised by chemical vapour deposition (CVD) have also been investigated. Controllable localized conversion from WS2 to WSxSe2-x alloy has been achieved by direct patterning on as-grown WS2 using energetic electron beam.