Determining Thermal Conductivity of Ti3C2Tx MXene and Ti3C2Tx/PVA Composite Films Using Power-Dependent Raman Spectroscopy

To obtain the thermal conductivity, polarized-laser power-dependent Raman spectra were recorded, as displayed in Figure 8a,b. The maximum laser power P0 was about 2.5 mW measured at the exit of the microscope lens and can be reduced using an optical attenuator. Obvious frequency red shift of the Raman peaks with increasing laser power was discovered, which arose from the local laser heating effect. Figure 8c,d show the red shift of the Eg1 mode frequency derived from the power-dependent Raman spectra. The ∂ω/∂p coefficients for the Ti3C2Tx MXene and Ti3C2Tx/PVA composite films are about 968 and 1081 cm–1/W, respectively. For two-dimensional materials with thin-film structure, the thermal conductivity can be expressed as... Unfortunately, the text provided does not mention the calculation method for the first temperature coefficient. Therefore, it is not possible to provide an answer to this question based on the given information.