Investigation of MPX₃ - Transition Metal Phosphorous Trichalcogenides

Transition metal Phosphorous Trichalcogenides (MPTs) are layered compounds with chemical formula MPX₃, where M is divalent metal, P is Phosphorous and X stands for chalcogenide atom (S, Se or Te). In the past bulk crystals of MPTs were widely studied for application i.e. in lithium batteries [1]. Nowadays they are once again in scientific interest due to their anisotropic properties and possibility to obtain and study their few and monolayers [2] and implementation them into first tests devices [3].

MPTs are two dimensional (2D) semiconductors, also called layered materials, as they are built from stacks of single molecular sheets. They have strong, covalent bonds within layer and between them there are only weak van der Waals interactions. The intra-layer interactions are 1-2 orders of magnitude stronger than inter-layer ones and this anisotropy of structure has great impact on their properties. For example, it is relatively simple to receive few or even monolayer forms or to intercalate these compounds. Moreover, such a decreasing of size in one dimensions leads to observing special phenomena in case of electrical or magnetic properties.

The poster will present synthesis and characterization of bulk, few and monolayers of Metal Phosphorous Trisulfides and Metal Phosphorous Triselenides, i.e. MnPS₃ or FePSe₃. Bulk crystals were obtained by vapor transport synthesis and exfoliation was performed micro-mechanical approach: “Scotch Tape Method”. Received products were characterized for example by SEM coupled with EDS, and Atomic Force Microscopy (AFM), Raman spectroscopy and Photoacoustic Spectroscopy (PAS).

Acknowledgments:

This work was supported by the European Comission via the Marie-Sklodowska Curie action Phonsi (H2020-MSCA-ITN-642656)

References:

[1] R. Brec, Solid State Ionics, 1986, vol. 22, no. 1, 1986.

[2] K.-z. Du et. al., ACS Nano, vol. 10, no. 2, 2016.

[3] G. Long et. al., ACS Nano, article ASAP, 2017.