Atomic-level control over ultrathin 2D layers of Transition Metal Dichalcogenides obtained by a Molecular Layer Deposition route
Published : 15 July 2019
2D-materials, especially transition metal dichalcogenides (TMD), have recently received considerable attention since they are emerging as a class of exceptional semiconductor materials with many potential applications (supercapacitors, batteries, electronics and opto-electronics, flexible electronics …). However, a sizeable bottleneck for their full deployment stems from the lack of scalable fabrication methods with atomic scale precision. Both Atomic Layer Deposition (ALD) and Molecular Layer Deposition (MLD) are based on sequential, self-limiting surface reactions that allow conformal film growth with precise thickness control. They are ideal techniques for depositing scalable ultrathin inorganic and organic films.
The thesis project aims to achieve the synthesis of intermediate layered metal-organic hybrid films by a combination of Atomic Layer Deposition and Molecular Layer Deposition (ALD/MLD) followed by mild thermal treatment (annealing) en route to the crystalline final phase. The targeted materials are first TiS2 then SnS2. We want to explore with the thermal treatment a possible route to synthesize graphitic interfaces which could allow new electrodes or electrical contacts. Provide an atomic-level insight and control over the growth by combining ab initio calculations (not to be performed by the PhD student) and in situ chemical and structural studies performed during the growth and thermal treatment, i.e. in situ X-ray absorption and scattering with custom-built equipment, in situ Raman scattering, residual gas analysis, ellipsometry