  The interplay among various collective electronic states such as
superconductivity (SC) and charge density wave (CDW) is of tremendous
significance in low-dimensional transition metal dichalcogenides. Thus far, a
consensus on the relationship between SC and CDW has not been established in
IrTe2, where either competing or collaboration pictures have been suggested in
the bulk or thick flakes. Here, we use the state-of-art Au-assisted exfoliation
method to overcome the obstacle of interlayer Te-Te bonding, cleaving the IrTe2
down to monolayer for the first time. A striking feature revealed by
angle-resolved polarized Raman spectroscopy (ARPRS) and electrical transport
measurements is the concurrence of phase separation in one single piece of
nano-flake, i.e. the superconducting (P-3m1) and CDW (P-3) area. In the pure SC
area, the dimensional fluctuations completely suppress the CDW ordering and
induce SC at 3.5 K. Meanwhile, the pure CDW area with much enhanced TCDW at 605
K (compared to TCDW = 280 K in bulk) is always accompanied by a unique wrinkle
pattern. Detailed analyses suggest the local strain-induced bond breaking of
the Te-Te dimer facilitates the emergence of the CDW order. Our works provide
compelling evidence of competition between SC and CDW, highlighting the
importance of microstructure in determining the ground states of IrTe2.
