標題: Large-Area 2D Layered MoTe2 by Physical Vapor Deposition and Solid-Phase Crystallization in a Tellurium-Free Atmosphere
作者: Huang, Jyun-Hong
Deng, Kuang-Ying
Liu, Pang-Shiuan
Wu, Chien-Ting
Chou, Cheng-Tung
Chang, Wen-Hao
Lee, Yao-Jen
Hou, Tuo-Hung
電子物理學系
電子工程學系及電子研究所
Department of Electrophysics
Department of Electronics Engineering and Institute of Electronics
關鍵字: molybdenum ditelluride (MoTe2);phase transition;physical vapor deposition;solid-phase crystallization;transition-metal dichalcogenides (TMDs)
公開日期: 8-Sep-2017
摘要: Molybdenum ditelluride (MoTe2) has attracted considerable interest for nanoelectronic, optoelectronic, spintronic, and valleytronic applications because of its modest band gap, high field-effect mobility, large spin-orbit-coupling splitting, and tunable 1T/2H phases. However, synthesizing large-area, high-quality MoTe2 remains challenging. The complicated design of gas-phase reactant transport and reaction for chemical vapor deposition or tellurization is nontrivial because of the weak bonding energy between Mo and Te. This study reports a new method for depositing MoTe2 that entails using physical vapor deposition followed by a postannealing process in a Te-free atmosphere. Both Mo and Te are physically deposited onto the substrate by sputtering a MoTe2 target. A composite SiO2 capping layer is designed to prevent Te sublimation during the postannealing process. The postannealing process facilitates 1T-to-2H phase transition and solid-phase crystallization, leading to the formation of high-crystallinity few-layer 2H-MoTe2 with a field-effect mobility of approximate to 10 cm(2) V-1 s(-1), the highest among all nonexfoliated 2H-MoTe2 currently reported. Furthermore, 2H-MoS2 and Td-WTe2 can be deposited using similar methods. Requiring no transfer or chemical reaction of metal and chalcogen reactants in the gas phase, the proposed method is potentially a general yet simple approach for depositing a wide variety of large-area, high-quality, 2D layered structures.
URI: http://dx.doi.org/10.1002/admi.201700157
http://hdl.handle.net/11536/146047
ISSN: 2196-7350
DOI: 10.1002/admi.201700157
期刊: ADVANCED MATERIALS INTERFACES
Volume: 4
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