Abstract
Two-dimensional materials with the Janus structures have attracted immense attention owing to their unique properties and promising prospects in electronics. This presentation delves into the fabrication and comprehensive characterization of various Janus transition metal dichalcogenides and nitrides.
We developed a controllable synthesis approach for monolayer Janus MoSeN and WSeTe on Au(111) by nitrogen plasma assisted molecular-beam epitaxy. Annular darkfield scanning transmission electron microscopy, electron diffraction, scanning tunneling microscopy, and x-ray photoelectron spectroscopy measurements validated the atomic configuration of Janus MoSeN and WSeTe. Their electronic attributes were examined through ultraviolet photoelectron spectroscopy, photoluminescence, scanning tunneling spectroscopy, and corroborated by density functional theory (DFT) calculations. Moreover, piezoresponse force microscopy measurements highlighted vertical piezoelectricity in Janus MoSeN and WSeTe. Interestingly, our DFT calculation showed that Janus nitrides such as 1H WSe/TeN, MoSe/TeN and NbSe/TeN could display superconductivity with critical temperatures more than 10K.
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