Articolo in rivista, 2020, ENG, 10.3390/nano10040803

Conductive atomic force microscopy of semiconducting transition metal dichalcogenides and heterostructures

Giannazzo F.; Schiliro E.; Greco G.; Roccaforte F.

CNR-IMM, Strada VIII, Catania, 5-5121, CNR-IMM, Strada VIII, 5-5121, Catania, Italy, , Italy

Semiconducting transition metal dichalcogenides (TMDs) are promising materials for future electronic and optoelectronic applications. However, their electronic properties are strongly affected by peculiar nanoscale defects/inhomogeneities (point or complex defects, thickness fluctuations, grain boundaries, etc.), which are intrinsic of these materials or introduced during device fabrication processes. This paper reviews recent applications of conductive atomic force microscopy (C-AFM) to the investigation of nanoscale transport properties in TMDs, discussing the implications of the local phenomena in the overall behavior of TMD-based devices. Nanoscale resolution current spectroscopy and mapping by C-AFM provided information on the Schottky barrier uniformity and shed light on the mechanisms responsible for the Fermi level pinning commonly observed at metal/TMD interfaces. Methods for nanoscale tailoring of the Schottky barrier in MoS for the realization of ambipolar transistors are also illustrated. Experiments on local conductivity mapping in monolayer MoS grown by chemical vapor deposition (CVD) on SiO substrates are discussed, providing a direct evidence of the resistance associated to the grain boundaries (GBs) between MoS domains. Finally, C-AFM provided an insight into the current transport phenomena in TMD-based heterostructures, including lateral heterojunctions observed within MoWSe alloys, and vertical heterostructures made by van der Waals stacking of different TMDs (e.g., MoS/WSe) or by CVD growth of TMDs on bulk semiconductors.

Nanomaterials (Basel) 10 , pp. 803-1–803-21

Keywords

Transition Metal Dichalcogenides, C-AFM, heterostructures, Schottky

CNR authors

Schiliro Emanuela, Roccaforte Fabrizio, Giannazzo Filippo, Greco Giuseppe

CNR institutes

IMM – Istituto per la microelettronica e microsistemi

ID: 424193

Year: 2020

Type: Articolo in rivista

Creation: 2020-06-20 15:41:56.000

Last update: 2021-04-07 23:39:17.000

External IDs

CNR OAI-PMH: oai:it.cnr:prodotti:424193

DOI: 10.3390/nano10040803

Scopus: 2-s2.0-85083703287