TY - JOUR
T1 - Nanomechanical absorption spectroscopy of 2D materials with femtowatt sensitivity
AU - Kirchhof, Jan N.
AU - Yu, Yuefeng
AU - Yagodkin, Denis
AU - Stetzuhn, Nele
AU - de Araújo, Daniel B.
AU - Kanellopulos, Kostas
AU - Manas-Valero, Samuel
AU - Coronado, Eugenio
AU - van der Zant, Herre
AU - More Authors, null
PY - 2023
Y1 - 2023
N2 - Nanomechanical spectroscopy (NMS) is a recently developed approach to determine optical absorption spectra of nanoscale materials via mechanical measurements. It is based on measuring changes in the resonance frequency of a membrane resonator vs. the photon energy of incoming light. This method is a direct measurement of absorption, which has practical advantages compared to common optical spectroscopy approaches. In the case of two-dimensional (2D) materials, NMS overcomes limitations inherent to conventional optical methods, such as the complications associated with measurements at high magnetic fields and low temperatures. In this work, we develop a protocol for NMS of 2D materials that yields two orders of magnitude improved sensitivity compared to previous approaches, while being simpler to use. To this end, we use mechanical sample actuation, which simplifies the experiment and provides a reliable calibration for greater accuracy. Additionally, the use of low-stress silicon nitride membranes as our substrate reduces the noise-equivalent power to NEP = 890 fW H z − 1 , comparable to commercial semiconductor photodetectors. We use our approach to spectroscopically characterize a 2D transition metal dichalcogenide (WS2), a layered magnetic semiconductor (CrPS4), and a plasmonic super-crystal consisting of gold nanoparticles.
AB - Nanomechanical spectroscopy (NMS) is a recently developed approach to determine optical absorption spectra of nanoscale materials via mechanical measurements. It is based on measuring changes in the resonance frequency of a membrane resonator vs. the photon energy of incoming light. This method is a direct measurement of absorption, which has practical advantages compared to common optical spectroscopy approaches. In the case of two-dimensional (2D) materials, NMS overcomes limitations inherent to conventional optical methods, such as the complications associated with measurements at high magnetic fields and low temperatures. In this work, we develop a protocol for NMS of 2D materials that yields two orders of magnitude improved sensitivity compared to previous approaches, while being simpler to use. To this end, we use mechanical sample actuation, which simplifies the experiment and provides a reliable calibration for greater accuracy. Additionally, the use of low-stress silicon nitride membranes as our substrate reduces the noise-equivalent power to NEP = 890 fW H z − 1 , comparable to commercial semiconductor photodetectors. We use our approach to spectroscopically characterize a 2D transition metal dichalcogenide (WS2), a layered magnetic semiconductor (CrPS4), and a plasmonic super-crystal consisting of gold nanoparticles.
KW - 2D materials
KW - nanomechanical resonators
KW - NEMS
KW - resonator
KW - silicon nitride
KW - spectroscopy
KW - transition metal dichalcogenides (TMDs)
UR - http://www.scopus.com/inward/record.url?scp=85158845014&partnerID=8YFLogxK
U2 - 10.1088/2053-1583/acd0bf
DO - 10.1088/2053-1583/acd0bf
M3 - Article
AN - SCOPUS:85158845014
SN - 2053-1583
VL - 10
JO - 2D Materials
JF - 2D Materials
IS - 3
M1 - 035012
ER -