1 research outputs found
Phase and Composition Engineering of Self-Intercalated 2D Metallic Tantalum Sulfide for Second-Harmonic Generation
Self-intercalation in two-dimensional (2D) materials
is significant,
as it offers a versatile approach to modify material properties, enabling
the creation of interesting functional materials, which is essential
in advancing applications across various fields. Here, we define ic-2D
materials as covalently bonded compounds that result from the self-intercalation
of a metal into layered 2D compounds. However, precisely growing ic-2D
materials with controllable phases and self-intercalation concentrations
to fully exploit the applications in the ic-2D family remains a great
challenge. Herein, we demonstrated the controlled synthesis of self-intercalated
H-phase and T-phase Ta1+xS2 via a temperature-driven chemical vapor deposition (CVD) approach
with a viable intercalation concentration spanning from 10% to 58%.
Atomic-resolution scanning transmission electron microscopy-annular
dark field imaging demonstrated that the self-intercalated Ta atoms
occupy the octahedral vacancies located at the van der Waals gap.
The nonperiodic Ta atoms break the centrosymmetry structure and Fermi
surface properties of intrinsic TaS2. Therefore, ic-2D
T-phase Ta1+xS2 consistently
exhibit a spontaneous nonlinear optical (NLO) effect regardless of
the sample thickness and self-intercalation concentrations. Our results
propose an approach to activate the NLO response of centrosymmetric
2D materials, achieving the modulation of a wide range of optoelectronic
properties via nonperiodic self-intercalation in the ic-2D family