1 research outputs found
Pulsed Carrier Gas Assisted High-Quality Synthetic 3<i>R</i>‑Phase Sword-like MoS<sub>2</sub>: A Versatile Optoelectronic Material
Synthesizing a material with the desired polymorphic
phase in a
chemical vapor deposition (CVD) process requires a delicate balance
among various thermodynamic variables. Here, we present a methodology
to synthesize rhombohedral (3R)-phase MoS2 in a well-defined sword-like geometry having lengths up to 120 μm,
uniform width of 2–3 μm and thickness of 3–7 nm
by controlling the carrier gas flow dynamics from continuous mode
to pulsed mode during the CVD growth process. Characteristic signatures
such as high degree of circular dichroism (∼58% at 100 K),
distinct evolution of low-frequency Raman peaks and increasing intensity
of second harmonic signals with increasing number of layers conclusively
establish the 3R-phase of the material. A high value
(∼844 pm/V) of second-order susceptibility for few-layer-thick
MoS2 swords signifies the potential of MoS2 to
serve as an atomically thin nonlinear medium. A field effect mobility
of 40 cm2/V-s and Ion/Ioff ratio of ∼106 further
confirm the electronic-grade standard of this 3R-phase
MoS2. These findings are significant for the development
of emerging quantum electronic devices utilizing valley-based physics
and nonlinear optical phenomena in layered materials