Molybdenum disulfide (MoS2) is one of the most commonly studied graphene-like 2D materials. Atomically thin MoS2 is a semiconductor with unique electrical, optical, and mechanical properties, which make it a useful material for piezoelectric, photovoltaic[6,7], and other optoelectronic applications.
In this application note, monolayer MoS2 grown by chemical vapor deposition (CVD) was imaged with Kelvin probe force microscopy (KPFM) using a Flex-Axiom to study the contact potential difference variation on a single crystal.
Monolayers of MoS2 were grown on a silicon substrate by chemical vapor deposition.
Sample courtesy: University of Illinois – Urbana-Champlain
Measurements using the Flex-Axiom show a step height of 0.6 nm for the MoS2 monolayer. Concurrent KPFM measurements show a 650 mV contact potential difference between the monolayer and the SiO2 substrate.
Non-uniformity of the contact potential signal across the monolayer can inform about doping profiles and other surface defects.
For more information contact our application scientists
 Subbaiah, Y.P.V., et al., Advanced Functional Materials 26 (2016) 2046
 Mak, K.F., et al., Physical Review Letters 105 (2010) 136805
 Splendiani, A., et al., Nano Letters 10 (2010) 1271
 Akinwande, D., Nature Communications 5 (2014) 56787
 Wu, W., et al., Nature 514 (2014) 470
 Tsai, M.-L., et al., ACSNano 8 (2014) 8317
 Wi, S., et al., ACS Nano 8 (2014) 5270
 Sanne, A., et al., Nano Letters 15 (2015) 5039
Nanosurf application note AN01154