Layered structures of Metal Sulphides

• Applicant: Professor Dr. Alexander Föhlisch
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2018 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 400335214

Sputter deposition is a commonly used process and the possibility of using it in conjunction with 2D materials would constitute an enormous advantage for the industrial scale production in Europe. This has, however, not been accomplished yet. The reason for this is the energetic particle bombardment associated with conventional sputtering which may easily break the weak bonds in these types of sensitive materials. The conventional sputtering process promotes energetic particle flux onto the growing film which is normally beneficial for the film quality but may be very detrimental to a fragile layered material. There is however a number of processing condition that can be modified to significantly reduce the energetic bombardment. By using Monte-Carlo based software that is capable of simulating the sputtering process together with experimental feedback, the aim is to develop a sputtering process that is compatible with the layered structures.In this project, we propose to develop a sputter-deposition method for deposition onto sensitive layered structures as well as for the actual deposition of high quality layered sulphide structures, such as WS2, MoS2, SnS2 and combinations thereof. Such materials combinations constitute novel layered materials structures and it is of major importance that such structures are developed in EU since large scale synthesis of 2D materials have been identified as a key factor for commercial uptake. Mixed 2D materials also offer “materials on demand”, i.e. that the final material properties may be tailored from the combination of constituents. The deposited films will further be characterised by using optical microscopy, atomic force microscopy (AFM), scanning tunnelling microscopy (STM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, Raman and photoluminescence spectroscopies, X-ray photoelectron spectroscopy (XPS) and hard X-ray photoelectron spectroscopy. Such characterisation is important for understanding the fundamental physics of the layered structures and hetero structures. Further, deposition and analysis of the proposed 2D materials is necessary to assess their potential in novel electronics and optoelectronics.The specific purposes and aims of the proposed project are as follows• Studying and characterising the influence of the energetic particle bombardment associated with sputter deposition onto the proposed 2D-materials.• Developing a sputter deposition process that enables deposition onto the proposed 2D-materials without deteriorating their quality.• Developing a sputter deposition process that enables deposition of high quality layered sulphide films, such as WS2, MoS2, SnS2, and novel combinations thereof• Characterising the sputtered 2D-materials films and evaluating them from a fundamental standpoint, e.g. correlation of the structural aspects (crystal structure and defects) with the fundamental electronic properties.

• DFG Programme: Research Grants
• International Connection: France, Sweden
• Cooperation Partners: Dr. Tomas Nyberg; Professorin Nadine Witkowski