Large-Area 2D Layered MoTe2 by Physical Vapor Deposition and Solid-Phase Crystallization in a Tellurium-Free Atmosphere

Jyun Hong Huang, Kuang Ying Deng, Pang Shiuan Liu, Chien Ting Wu, Cheng Tung Chou, Wen-Hao Chang, Yao Jen Lee, Tuo-Hung Hou*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

25 Scopus citations

Abstract

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 ≈10 cm2 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.

Original languageEnglish
Article number1700157
JournalAdvanced Materials Interfaces
Volume4
Issue number17
DOIs
StatePublished - 8 Sep 2017

Keywords

  • molybdenum ditelluride (MoTe)
  • phase transition
  • physical vapor deposition
  • solid-phase crystallization
  • transition-metal dichalcogenides (TMDs)

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