2D Monolayer of 1T' Phase of Alloyed WSSe from Colloidal Synthesis

Ashkan Shahmanesh (1) , Davide Romanin (2) , Corentin Dabard (3, 4) , Sang-Soo Chee (4) , Charlie Gréboval (4) , Christophe Methivier (5) , Mathieu G Silly (6) , Julien Chaste (7) , Matthieu Bugnet (8) , Debora Pierucci (7) , Abdelkarim Ouerghi (7) , Matteo Calandra (9) , Emmanuel Lhuillier (4) , Benoit Mahler (1)

1 iLM - LUMINESCENCE - iLM - Luminescence
2 INSP-E2 - Spectroscopie des nouveaux états quantiques
3 LPEM - Laboratoire de Physique et d'Etude des Matériaux (UMR 8213)
4 INSP-E6 - Physico-chimie et dynamique des surfaces
5 LRS - Laboratoire de Réactivité de Surface
6 SSOLEIL - Synchrotron SOLEIL
7 C2N - Centre de Nanosciences et de Nanotechnologies
8 MATEIS - Matériaux, ingénierie et science [Villeurbanne]
9 UNITN - Università degli Studi di Trento = University of Trento

We explore the colloidal growth of monolayers of WSSe alloy in their 1T' phase with various Se content. We develop a synthetic procedure leading to reduced aggregation of the flakes. The presence of a narrow band-gap close to the top of the valence band has been evidenced combining photoemission spectroscopy and density functional theory (DFT). The electronic structure is weakly affected by the variation of the alloy content and atomic ordering. µ-Raman spectroscopy and STEM are used to confirm the obtained 1T' phase, while simulations of the Raman spectra suggest contribution from both the S and Se atoms in the Raman spectra. Finally, we use electronic transport and photoconduction and reveal a short coherence length consistent with the defective nature of the flakes.

Keywords: Transition metal dichalcogenides; 2D monolayer; Density Functional Theory; Raman; Photoemission

Domains: Material chemistry; Condensed Matter [cond-mat]

Ashkan Shahmanesh, Davide Romanin, Corentin Dabard, Sang-Soo Chee, Charlie Gréboval, et al.. 2D Monolayer of 1T' Phase of Alloyed WSSe from Colloidal Synthesis. Journal of Physical Chemistry C, 2021, 125 (20), pp.11058-11065. ⟨10.1021/acs.jpcc.1c02275⟩. ⟨hal-03227064⟩