Preparation of MoS₂ layers opens up new possibilities in electronics

Two-dimensional (2D) molybdenum disulfide (MoS₂) has attracted widespread attention due to its unique electronic, mechanical and optical properties. It is a material composed of several atomic layers of MoS₂ held together by van der Waals forces.

Our colleagues from the Department of Microelectronics and Sensors have prepared high-quality 2-5 monolayer thick MoS₂ layers on sapphire and GaN/sapphire substrates using pulsed laser deposition (PLD). GaN is a wide bandgap semiconductor and the ideal material of choice for high-frequency transistors  and power-switching devices, as well as for optoelectronic devices. We performed a detailed analysis of the orientation relationship between the MoS₂ film and the c-sapphire and GaN substrates, for which few results are only available in the literature. The prepared MoS₂ films are of excellent crystalline quality and thickness homogeneity, and we were able to prepare them on large-area surfaces. Furthermore, we provided a detailed electrical investigation of the in-plane transport properties of PLD-grown MoS₂ films on insulating sapphire substrates, extracting key physical parameters like the ionization energy of donors and providing insight into the limiting mechanisms of carrier mobility. To the best of our knowledge, this type of investigation has been not reported so far in PLD-grown MoS₂.

The results are useful for benchmarking the electronic quality of the material produced by this approach compared to that of MoS₂ produced by alternative methods.

Schematic representation of the orientation relationship between c-plane sapphire, GaN, and MoS₂ and ϕ -scans of the  MoS₂ planes.

More: https://doi.org/10.3390/nano13212837

Authors: M. Španková, Š. Chromik, E. Dobročka, L. Pribusová Slušná, M. Talacko, M. Gregor, B. Pécz, A. Koos, G. Greco, S.E. Panasci, P. Fiorenza, F. Roccaforte, Y. Cordier, E. Frayssinet, F. Giannazzo