Yi Wan

Measuring the Refractive Index of Highly Crystalline Monolayer MoS2 with High Confidence

Monolayer molybdenum disulphide (MoS2) has attracted much attention, due to its attractive properties, such as two-dimensional properties, direct bandgap, valley-selective circular dichroism, and valley Hall effect. However, some of its fundamental physical parameters, e.g. refractive index, have not been studied in detail because of measurement difficulties. In this work, we have synthesized highly crystalline monolayer MoS2 on SiO2/Si substrates via chemical vapor deposition (CVD) method and devised a method to measure their optical contrast spectra. Using these contrast spectra, we extracted the complex refractive index spectrum of monolayer MoS2 in the wavelength range of 400u2005nm to 750u2005nm. We have analyzed the pronounced difference between the obtained complex refractive index spectrum and that of bulk MoS2. The method presented here is effective for two-dimensional materials of small size. Furthermore, we have calculated the color contour plots of the contrast as a function of both SiO2 thickness and incident light wavelength for monolayer MoS2 using the obtained refractive index spectrum. These plots are useful for both fundamental study and device application.

Physical origin of Davydov splitting and resonant Raman spectroscopy of Davydov components in multilayer MoTe 2

We systematically study the high-resolution and polarized Raman spectra of multilayer (ML)

The In-Plane Anisotropy of WTe2 Investigated by Angle-Dependent and Polarized Raman Spectroscopy

{mathrm{MoTe}}_{2}

Ultrasensitive Near-Infrared Photodetectors Based on a Graphene–MoTe2–Graphene Vertical van der Waals Heterostructure

. The layer-breathing (LB) and shear (C) modes are observed in the ultralow-frequency region, which are used to quantitatively evaluate the interlayer coupling in ML

Origin of Improved Optical Quality of Monolayer Molybdenum Disulfide Grown on Hexagonal Boron Nitride Substrate

{mathrm{MoTe}}_{2}

Interference effect on optical signals of monolayer MoS2

based on the linear chain model, in which only the nearest interlayer coupling is considered. The Raman spectra on three different substrates verify the negligible substrate effect on the phonon frequencies of ML

Large-Scale Synthesis and Systematic Photoluminescence Properties of Monolayer MoS2 on Fused Silica

{mathrm{MoTe}}_{2}

Epitaxial Single-Layer MoS2 on GaN with Enhanced Valley Helicity

. Ten excitation energies are used to measure the high-frequency modes of

Fully Transparent Quantum Dot Light-Emitting Diode with a Laminated Top Graphene Anode

N

High-quality InSb nanocrystals: synthesis and application in graphene-based near-infrared photodetectors

-layer