Image of the Month

June 2017

Chemical vapor deposition growth of bilayer graphene in between molybdenum disulfide sheets

Fig. 2. STM topography image of carbon-induced islands intercalated between MoS2 layers and Current-voltage (I(V)) spectroscopy curves recorded on top of an island and on the surrounding MoS2 layer. The same characteristic I(V) behavior is measured, which unequivocally demonstrates that the island is intercalated and is covered with the same material as the surroundings, i.e., MoS2. The I(V) curves appear to be metallic, since the set point used in order to record them is within the band gap of MoS2. The set points are 0.2 nA, 0.5 V

Direct growth of flat micrometer-sized bilayer graphene islands in between molybdenum disulfide sheets is achieved by chemical vapor deposition of ethylene at about 800 _C. The temperature assisted decom- position of ethylene takes place mainly at molybdenum disulfide step edges. The carbon atoms interca- late at this high temperature, and during the deposition process, through defects of the molybdenum disulfide surface such as steps and wrinkles. Post growth atomic force microscopy images reveal that cir- cular flat graphene islands have grown at a high yield. They consist of two graphene layers stacked on top of each other with a total thickness of 0.74 nm. Our results demonstrate direct, simple and high yield growth of graphene/molybdenum disulfide heterostructures, which can be of high importance in future nanoelectronic and optoelectronic applications.

2017 Elsevier Inc. All rights reserved.

Journal of Colloid and Interface Science 505 (2017): 776-782.

Wojciech Kwieciñskia,b, Kai Sotthewesa, Bene Poelsemaa, Harold J.W. Zandvlieta, Pantelis Bampoulisa,c

aPhysics of Interfaces and Nanomaterials, MESA+Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands

bFaculty of Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
cPhysics of Fluids and J.M. Burgers Centre for Fluid Mechanics, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands