The 85th Meeting of the Israel Chemical Society

Exfoliated CrPS4 with promising photoconductivity

Adam K. Budniak 1 Niall A. Killilea 2 Szymon J. Zelewski 3 Mykhailo Sytnyk 2 Yaron Kauffmann 4 Yaron Amouyal 4 Robert Kudrawiec 3 Wolfgang Heiss 2 Efrat Lifshitz 1
1Schulich Faculty of Chemistry, Solid State Institute, Russell Berrie Nanotechnology Institute, Technion – Israel Institute of Technology, Haifa, Israel
2Materials Science Department, Energy Campus Nurnberg, Friedrich-Alexander Universitat Erlangen-Nurnberg, Nurnberg, Germany
3Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
4Department of Materials Science and Engineering, Technion – Israel Institute of Technology, Haifa, Israel

Layered semiconductors attract significant attention due to their diverse physical properties controlled by their composition and the number of stacked layers. Herein, large crystals of the ternary layered semiconductor chromium thiophosphate (CrPS4) are prepared by a vapor transport synthesis. Optical properties are determined using photoconduction, absorption, photoreflectance, and photoacoustic spectroscopy exposing the semiconducting properties of the material. A simple, one-step protocol for mechanical exfoliation onto transmission electron microscope grid is developed and multiple layers are characterized by advanced electron microscopy methods, including atomic resolution elemental mapping confirming the structure by directly showing the positions of the columns of different elements’ atoms. CrPS4 is also liquid exfoliated and in combination with colloidal graphene, an ink-jet printed photodetector is created. This all-printed graphene/CrPS4/graphene heterostructure detector demonstrates specific detectivity of 8.3×108 (D*). This study shows a potential application of both bulk crystal as well as individual flakes of CrPS4 as active components in light detection, when introduced as ink printable moieties with a large benefit for manufacturing [1].

test of description

A: Atomic resolution HAADF-STEM micrograph of a mechanically exfoliated CrPS4 crystal. The inset presents the simulated structure showing the position of the atom columns of chromium (red spheres), phosphorous (blue spheres) and sulfur (green spheres). B: HAADF-STEM micrographs close to A area. C-E: EDS elemental maps (averaged) of the area in B showing the atomic distribution of the Cr, P and S respectively; F: EDS elemental maps of chromium and phosphorous overlapped on HAADF picture. Sulfur atoms were omitted for clarity. It is clearly seen, that columns of chromium atoms are arranged rectangularly and columns of phosphorous atoms in "zig-zag" way (guide lines and distances between columns of atoms were added for convenience).

References:

[1] A.K. Budniak, N.A. Killilea, S.J. Zelewski, M. Sytnyk, Y. Kauffmann, Y. Amouyal, R. Kudrawiec, W. Heiss, E. Lifshitz; Small, 2019, 1905924, 1–10, "Article in Press"









Powered by Eventact EMS