P.G. acknowledges the partial support from the U.S. Air Force Office of Scientific Research (grant no. FA9550-22-1-0209) and Yale University’s lab set-up fund. M.F.-D. acknowledges support from the Natural Sciences and Engineering Research Council of Canada (NSERC) and Fonds de recherche du Québec (FRQNT). M.F.D. and F.X. acknowledge the partial support from Government of Israel. K.W. and T.T. acknowledge support from JSPS KAKENHI (grant numbers 19H05790, 20H00354, and 21H05233). Y.X. and H.L. gratefully acknowledge the startup fund provided by Portland State University.
The Journal of Physical Chemistry C
Electrical conductivity, Heat transfer, Heterostructures, Optical properties, Quantum mechanics
Two-dimensional (2D) transition metal chalcogenides (TMDs) have drawn significant attention in recent years due to their extraordinary optical and electronic properties. As heat transfer plays an important role in device performance, various methods such as optothermal Raman spectroscopy and time-domain thermoreflectance have been developed to measure the thermal conductivity and interfacial thermal conductance in 2D van der Waals (vdW) heterostructures. Here, we employ the vibrational-pump-visible-probe (VPVP) spectroscopy to directly visualize the heat transfer process in a heterostructure of multilayer h-BN and monolayer WS2. Following an impulsive vibrational excitation of h-BN in the mid-infrared, we probe the heat transfer from h-BN through WS2 and finally to the substrate from the subpicosecond to the submicrosecond timescale. The interfacial thermal conductance of the h-BN/WS2 and WS2/SiO2 interfaces is obtained by corroborating the experiments with heat transfer calculations based on the Fourier’s law of heat conduction. Our study demonstrates an alternative, time-resolved optical method to measure cross-plane heat dissipation and opens up a new pathway to investigate the interlayer electron–phonon and phonon–phonon interactions in vdW heterostructures.
© Copyright the author(s)
Locate the Document
Published as: Chen, D., Fortin-Deschênes, M., Lou, Y., Lee, H., Xu, J., Sheikh, A. A., ... & Guo, P. (2023). Direct Spectroscopic Observation of Cross-Plane Heat Transfer in a Two-Dimensional Van der Waals Heterostructure. The Journal of Physical Chemistry C.