Berlin 2024 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 40: 2D Materials and Heterostructures: Magnetic Properties

HL 40.6: Vortrag

Donnerstag, 21. März 2024, 10:45–11:00, EW 201

Spectral-imaging of 2D magnetic semiconductor V-WS2 using ToF-XPEEM — Q. Nguyen¹, O. Tkach^2,3, O. Fedchenko², S. Chernov⁴, Z. Zhang⁵, L. Hoang⁵, M. Prandolini⁴, D. Kutnyakhov⁴, F. Pressacco⁴, J. Dilling^4,7, L. Bruckmeier^4,7, M. Scholz⁴, F. Scholz⁴, C. Schlueter⁴, K. Rossnagel^4,7, M. Kling^1,5, M. Hoesch⁴, E. Pop⁵, A. Mannix⁵, T. Gorkhover^4,8, M. Dunne^1,5, N. Sirica⁶, R. Schoenlein¹, •H.-J. Elmers², and G. Schoenhense² — ¹SLAC Nat. Accel. Lab., USA — ²Univ. Mainz — ³SumDU, Ukraine — ⁴DESY — ⁵Stanford Univ., USA — ⁶Los Ala. Nat. Lab., USA — ⁷CAU Kiel — ⁸Univ. Hamburg

Using x-ray element-selective, time-of-flight photoemission electron microscopy (ToF-XPEEM), we characterize the spatial distribution and spectroscopic signatures of p-type vanadium dopant within the 2D semiconductor WS2 - achieving unprecedented 1.0-micron spatial resolution. Multilayer WS2 islands ranging from 3 - 20-micron in lateral size are grown via hybrid metal-organic chemical vapor deposition with nominal vanadium dopant concentrations ranging from 4 to 30 atom%. Combined with the soft x-ray energies at PETRA III - P04, ToF-XPEEM measurements reveal unique elemental spectroscopic signatures that reflect the stoichiometry within each island - which is important for optimizing the growth of these semiconductors. The spatial maps unravel the atomic positions of vanadium and tungsten within the 2D flakes at different doping concentration. Complementary full-field, hard x-ray photoelectron diffraction measured at PETRA III - P22 and Bloch wave calculations reveal the structural properties.

Keywords: 2D magnetic semiconductor; spectral-imaging; microscopy; x-ray