Nanomechanical spectroscopy of 2D materials

Abstract

We introduce a nanomechanical platform for fast and sensitive measurements of the spectrally-resolved optical dielectric function of 2D materials. At the heart of our approach is a suspended 2D material integrated into a nanomechanical resonator illuminated by a wavelength-tunable laser source. From the heating-related frequency shift of the resonator as well as its optical reflection measured as a function of photon energy, we obtain the real and imaginary parts of the dielectric function. Our measurements are unaffected by substrate-related screening and do not require any assumptions on the underling optical constants. This fast (${\tau }_{rise}$ $\sim$ 135 ns), sensitive (noise-equivalent power = 90 $\frac{pW}{\sqrt{Hz}}$ ), and broadband (1.2 $-$ 3.1 eV, extendable to UV-THz) method provides an attractive alternative to spectroscopic or ellipsometric characterisation techniques.

References in corpus (8)

• 2D materials and van der Waals heterostructures
• Measurement of the optical dielectric function of transition metal dichalcogenide monolayers: MoS2, MoSe2, WS2 and WSe2
• Evidence of high-temperature exciton condensation in 2D atomic double layers
• Broad Band Optical Properties of Large Area Monolayer CVD Molybdenum Disulfide
• Photonic crystals to enhance light extraction from 2D materials
• Tunable graphene phononic crystal
• Ultrawide Frequency Tuning of Atomic Layer van der Waals Heterostructure Electromechanical Resonators
• Tunable exciton-optomechanical coupling in suspended monolayer MoSe2

Cited by in corpus (2)

• Strain control of hybridization between dark and localized excitons in a 2D semiconductor
• Sub-ppm Nanomechanical Absorption Spectroscopy of Silicon Nitride