Raman spectroscopy-based temperature sensing usually tracks the change of Raman wavenumber, linewidth and intensity, and has found very broad applications in characterizing the energy and charge transport in nanomaterials over the last decade. The temperature coefficients of these Raman properties are highly material-dependent, and are subjected to local optical scattering influence. As a result, Raman-based temperature sensing usually suffers quite large uncertainties and has low sensitivity. Here, a novel method based on dual resonance Raman phenomenon is developed to precisely measure the absolute temperature rise of nanomaterial (nm WS₂ film in this work) from 170 to 470 K. A 532 nm laser (2.33 eV photon energy) is used to conduct the Raman experiment. Its photon energy is very close to the excitonic transition energy of WS₂ at temperatures close to room temperature. A parameter, termed resonance Raman ratio (R3) is introduced to combine the temperature effects on resonance Raman scattering for the A_1g and E_2g modes. Ω has a change of more than two orders of magnitude from 177 to 477 K, and such change is independent of film thickness and local optical scattering. It is shown that when Ω is varied by 1%, the temperature probing sensitivity is 0.42 K and 1.16 K at low and high temperatures, respectively. Based on Ω, the in-plane thermal conductivity (k) of a ~25 nm-thick suspended WS₂ film is measured using our energy transport state-resolved Raman (ET-Raman). k is found decreasing from 50.0 to 20.0 Wm⁻¹ K⁻¹ when temperature increases from 170 to 470 K. This agrees with previous experimental and theoretical results and the measurement data using our FET-Raman. The R3 technique provides a very robust and high-sensitivity method for temperature probing of nanomaterials and will have broad applications in nanoscale thermal transport characterization, non-destructive evaluation, and manufacturing monitoring.

It is desirable to fabricate materials with adjustable physical properties that can be used in different industrial applications. Since the property of a material is highly dependent on its inner structure, the understanding of structure–property correlation is critical to the design of engineering materials. 3D printing appears as a mature method to effectively produce micro-structured materials. In this work, we created different stainless-steel microstructures by adjusting the speed of 3D printing and studied the relationship between thermal property and printing speed. Our microstructure study demonstrates that highly porous structures appear at higher speeds, and there is a nearly linear relationship between porosity and printing speed. The thermal conductivity of samples fabricated by different printing speeds is characterized. Then, the correlation between porosity, thermal conductivity, and scanning speed is established. Based on this correlation, the thermal conductivity of a sample can be predicted from its printing speed. We fabricated a new sample at a different speed, and the thermal conductivity measurement agrees well with the value predicted from the correlation. To explore thermal transport physics, the effects of pore structure and temperature on the thermal performance of the printed block are also studied. Our work demonstrates that the combination of the 3D printing technique and the printing speed control can regulate the thermophysical properties of materials.