Periodic Reporting for period 4 - ALDof 2DTMDs (Atomic layer deposition of two-dimensional transition metal dichalcogenide nanolayers)
Reporting period: 2020-02-01 to 2020-12-31
Building upon pure 2D-TMDs, even more functionalities can be gained from 2D-TMD alloys and heterostructures. Theoretical work on these derivates reveals exciting new phenomena, but experimentally this field is largely unexplored due to synthesis technique limitations.
The goal of this project is to combine atomic layer deposition (ALD) with plasma chemistry to create a novel surface-controlled, industry-compatible synthesis technique that will make large area 2D-TMDs, 2D-TMD alloys and 2D-TMD heterostructures a reality. This innovative approach will enable systematic layer dependent studies, likely revealing exciting new properties, and provide integration pathways for a multitude of applications.
We have shown that tunability and control over the electrical and electronic properties of TMDs can be realized by alloying and doping these materials using ALD by switching between different ALD processes during deposition.
Patterned growth of 2DTMDS have been developed by using a combination of oxide ALD and thermal sulfurization, avoiding patterning and etching of the 2DTMD and selective ALD.
Nanometer-thick 2D TMD heterostructures consisting of TiS2-NbS2 on both planar and 3D structures using atomic layer deposition (ALD) at low temperatures (200−300 °C) have been successfully synthesized. Precise thickness control of the individual TMDC material layers was demonstrated by fabricating multilayer (5-layer) TiS2-Nb2x heterostructures with independently varied layer thicknesses.