Phase-Engineered Synthesis of Centimeter-Scale 1T'- and 2H-Molybdenum Ditelluride Thin Films.

Park, Jin Cheol; Yun, Seok Joon; Kim, Hyun; Park, Ji-Hoon; Chae, Sang Hoon; An, Sung-Jin; Kim, Jeong-Gyun; Kim, Soo Min et al. · ACS Nano · 2015

basic_science · Level V

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Abstract

We report the synthesis of centimeter-scale, uniform 1T'- and 2H-MoTe2 thin films via the tellurization of Mo thin films. 1T'-MoTe2 was initially grown and converted gradually to 2H-MoTe2 over a prolonged growth time under a Te atmosphere. Maintaining excessive Te was essential for obtaining the stable stoichiometric 2H-MoTe2 phase. Further annealing under a lower partial pressure of Te at the same temperature, followed by a rapid quenching, led to the reverse phase transition from 2H-MoTe2 to 1T'-MoTe2. The orientation of the 2H-MoTe2 film was determined by the tellurization rate. Slow tellurization was the key for obtaining a highly oriented 2H-MoTe2 film over the entire area, while fast tellurization led to a 2H-MoTe2 film with a randomly oriented c-axis.