Salt-assisted phase transformation of transition metal dichalcogenides

Abstract

A one-step salt-assisted general synthetic methodology for the controlled phase transformation of various types of 2H-phase transition metal dichalcogenides (2H-TMDs), yielding large-scale metastable 1T′-phase transition metal dichalcogenides (1T′-TMDs), including WS2, WSe2, MoS2, and MoSe2 is described. By tuning the reaction conditions, alloyed 1T′-TMDs such as WS2xSe2(1−x) and MoS2xSe2(1−x) are also obtained. Commercially-available metal salts such as K2C2O4·H2O, Na2C2O4, K2CO3, Na2CO3, Cs2CO3, Rb2CO3, KHCO3, and NaHCO3, are demonstrated to be effective for the controlled phase transformation at elevated temperatures in a reducing atmosphere. The technique may be extended to the phase engineering of other materials with various polymorphs.

Dependencies are inferred from the claim text.