[Research News] Discovery of a tellurium-catalyzed catalyst for monolayer disulfide transition metal
- 성균융합원
- Hit2296
- 2018-01-24
Discovery of a tellurium-catalyzed catalyst for monolayer disulfide transition metal
Center for Integrated Nanostructure Physics(CINP) succeeded in develping a method of replacing sulfur of monolayer molybdenum disulfide synthesized by chemical vapor deposition with tellurium and converting it into iturium and molybdenum.
In order to induce such a substitution reaction, a reaction at a high temperature is required. Since the metals of the tellurium transition metal have low thermal stability, there is a problem that the MoTe2 material becomes unstable when the MoS2 is substituted with MoTe2. MoTe2, which is the product after substitution, is thermally unstable at about 700 ° C and vaporizes. The difficulty is that the substitution reaction does not occur at temperatures below 700 ° C. To solve this problem, introduction of sodium tellurium (Na2Te), which is a tellurium catalyst, resulted in a substitution reaction even at low temperature (less than 700 ° C) and a stable phase of MoTe2 was obtained.
The team found that the tellurium-substitution reaction takes precedence over the edge of the MoS2 crystal, which could be used to make a hetero semiconductor junction (MoS2-MoTe2). Various conditions (MoS2-xTex alloy, semiconducting 2H-MoTe2, and metallic 1T'-MoTe2) were obtained by controlling experimental conditions. It is also shown that the composition of MoS2-xTex alloy can be controlled to control its band gap.
Dr. Yoon Seok-joon, who led the study, predicted that even if the compound is actually unstable, it is possible to synthesize the compound using this substitution method, and to synthesize the compound that does not exist in nature.
This research results were published on December 18 in Nature Communications(IF 12.124), a worldwide scientific journal in science and technology.