  Two-dimensional (2D) palladium ditelluride (PdTe2) and platinum ditelluride
(PtTe2) are two Dirac semimetals which demonstrate fascinating quantum
properties such as superconductivity, magnetism and topological order,
illustrating promising applications in future nanoelectronics and
optoelectronics. However, the synthesis of their monolayers is dramatically
hindered by strong interlayer coupling and orbital hybridization. In this
study, an efficient synthesis method for monolayer PdTe2 and PtTe2 is
demonstrated. Taking advantages of the surface reaction, epitaxial growth of
large-area and high quality monolayers of PdTe2 and patterned PtTe2 is achieved
by direct tellurization of Pd(111) and Pt(111). A well-ordered PtTe2 pattern
with Kagome lattice formed by Te vacancy arrays is successfully grown.
Moreover, multilayer PtTe2 can be also obtained and potential excitation of
Dirac plasmons is observed. The simple and reliable growth procedure of
monolayer PdTe2 and patterned PtTe2 gives unprecedented opportunities for
investigating new quantum phenomena and facilitating practical applications in
optoelectronics.
