Synthesis of MoS2 Thin Film
Many researchers have been used various methods such as mechanical exfoliation (B. Radisavljevic, et al., 2011), sulfurization (Y. Zhan, et al., 2012), chemical vapor deposition (CVD)(Y. H. Lee, et al., 2012; Y. Shi, et al., 2012) to grow MoS2 thin film. In the case of mechanical exfoliation, excellent electrical properties were shown. However, there is limitation of mass production. CVD method is a typical method and there are many reports. However, the method for large area MoS2growth on dielectric substrate at the relatively low temperature is not reported.
In this work, we successfully have grown a few layer MoS2 thin film (Fig. 1) on a SiO2 substrate using molybdenum hexacarbonyl (Mo(CO)6) and hydrogen disulfide (H2S) by a CVD method. The large area MoS2 thin film was grown by optimization of the Mo and S precursor ratio and growth conditions such as process pressure and temperature. The properties of the films were analyzed using atomic force microscope (AFM), transmission electron microscope (TEM), and Raman spectroscopy.
K. F. Mak, C. Lee, J. Hone, J. Shan, and T. F. Heinz, Atomically thin MoS2: a new direct-gap semiconductor, Phys. Rev. Lett., 105, 136805 (2010).
B. Radisavljevic, A. Radenovic, J. Brivio, V. Giacometti, and A. Kis, Single-layer MoS2 transistors, nature nanotechnology, 6, 147-150 (2011).
Y. Zhan, Z. Liu, S. Najmaei, P. M. Ajayan, and J. Lou, Large-Arae Vapor-Phase Growth and Characterization of MoS2 Atomic Layers on a SiO2 substrate, small, 8, 7, 966-971 (2012).
Y. H. Lee, X. Q. Zhang, W. Zhang, M. T. Chang, C. T. Lin, K. D. Chang, Y. C. Yu, J. T. Wang, C. S. Chang, L. J. Li, and T. W. Lin, Synthesis of Large-Area MoS2 Atomic Layers with Chemical Vapor Deposition, Advanced Materials, 24, 17, 2320-2325 (2012).
Y. Ishikawa and K. Kawakami, Structure and Infrared Spectroscopy of Group 6 Transition-Metal Carbonyls in the Gas Phase: DFT Studies on M(CO)n (M = Cr, Mo, and W; n = 6, 5, 4, and 3), J. Phys. Chem. A, 111, 9940-9944 (2007)