| AVS 62nd International Symposium & Exhibition | |
| 2D Materials Focus Topic | Tuesday Sessions |
| Session 2D+EM+MC+MI+NS+SP+SS+TF-TuA |
| Session: | Electronic and Magnetic Properties of 2D Materials |
| Presenter: | Olivier Renault, Univ. Grenoble Alpes/ CEA, LETI, MINATEC Campus, France |
| Authors: | O.J. Renault, Univ. Grenoble Alpes/ CEA, LETI, MINATEC Campus, France M. Frégnaux, Univ. Grenoble Alpes/ CEA, LETI, MINATEC Campus, France J. Bleuse, Univ. Grenoble-Alpes & CEA-INAC, France H. Kim, Univ. Grenoble Alpes/ CEA, LETI, MINATEC Campus, France D. Voiry, Rutgers University M. Chhowalla, Rutgers University |
| Correspondent: | Click to Email |
Within the perspective of integrating two-dimensional transition metal dichalcogenides (2D TMDs) such as molybdenum disulfide (MoS2), into devices, it becomes of utmost importance to assess the influence of each step of the device fabrication process on the optical and transport properties of the MoS2 single layer (1L) domains. Particularly at the deposition stage the properties may be influenced by substrate effects [1], and later, transfer processes may further alter the desired properties of TMDs. This requires effective microscopic characterization techniques.
We present a characterization method combining photoemission microscopy (XPEEM and Kpeem) and photoluminescence microscopy to compare the structural, optical and electronic properties of both as-deposited and transferred MoS2 1L domains onto different substrates. XPEEM is used with laboratory sources in both direct space imaging for work function and core-level mapping [2] and particularly in the momentum microscopy mode (k-PEEM) to perform parallel angular imaging and retrieve the band structure in a one shot experiment [3]. Micro-photoluminescence spectroscopy at low (5K) and room temperature is used to detect the specific radiative recombination that occurs in MoS2 1L (direct band gap semiconductor behavior) and to evidence the eventual presence of midgap states caused by process-induced defects. The results of both characterization techniques will be presented for MoS2 1L domains transferred onto silica and gold substrates highlighting the roles of substrate nature (metal or insulant), surface roughness, and the presence of structural defects whether induced by the preparation process or intrinsic such as grain boundaries.
[1] Jin et al. Phys. Rev. Lett. 111 (2013), 106801.
[2] Kim, Renault, et al. Appl. Phys. Lett. 105 (2014) 011605.
[3] Mathieu et al., PRB 83 (2011) 235436.