Type
ArticleAuthors
Han, AliAljarb, Areej
Liu, Sheng
Li, Peng

Ma, Chun
Xue, Fei
Lopatin, Sergei

Yang, Chih-Wen

Huang, Jing-Kai
Wan, Yi

Zhang, Xixiang

Xiong, Qihua
Huang, Kuo-Wei

Tung, Vincent

Anthopoulos, Thomas D.

Li, Lain-Jong

KAUST Department
Chemical Science ProgramElectron Microscopy
Homogeneous Catalysis Laboratory (HCL)
KAUST Catalysis Center (KCC)
KAUST Solar Center (KSC)
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division
Date
2019Permanent link to this record
http://hdl.handle.net/10754/656499
Metadata
Show full item recordAbstract
Bilayers of two-dimensional (2D) transition metal chalcogenides (TMDs) such as WSe2 have been attracting increasing attention owing to the intriguing properties involved in the different stacking configurations. The growth of bilayer WSe2 by chemical vapor deposition (CVD) has been facilely obtained without proper control of the stacking configuration. Herein, we report the controlled growth of bilayer WSe2 crystals as large as 30 μm on c-plane sapphire by the CVD method. Combining second harmonic generation (SHG), low-frequency Raman and scanning transmission electron microscopy (STEM), we elucidate the as-grown bilayer WSe2 with a 2H stacking configuration. Atomic force microscope (AFM) measurements reveal that the prominent atomic steps provide the energetically favorable templates to guide the upper layer nuclei formation, resembling the “graphoepitaxial effect” and facilitating the second WSe2 layer following the layer-by-layer growth mode to complete the bilayer growth. Field-effect charge transport measurement performed on bilayer WSe2 yields a hole mobility of up to 40 cm2 V−1 s−1, more than 3× higher than the value achieved in monolayer WSe2-based devices. Our study provides key insights into the growth mechanism of bilayer WSe2 crystals on sapphire and unlocks the opportunity for potential bilayer and multilayer TMD electronic applications.Citation
Han, A., Aljarb, A., Liu, S., Li, P., Ma, C., Xue, F., … Li, L.-J. (2019). Growth of 2H stacked WSe2 bilayers on sapphire. Nanoscale Horizons. doi:10.1039/c9nh00260jSponsors
T. D. A., V. T., X. Z., and L. L. acknowledge the support from King Abdullah University of Science and Technology. V. T. acknowledges the support from User Proposals (#4420 and #5067) at the Molecular Foundry, Lawrence Berkeley National Lab, supported by the Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. We would also like to acknowledge the support from Core Lab in KAUST.Publisher
Royal Society of Chemistry (RSC)Journal
Nanoscale HorizonsAdditional Links
http://xlink.rsc.org/?DOI=C9NH00260Jae974a485f413a2113503eed53cd6c53
10.1039/c9nh00260j