Investigation of the anharmonic phonon effects in 2H–MoTe₂ crystal is crucial, not only for understanding its phonon-mediated heat transport but also for developing MoTe₂-based functional devices with high performance. Here, through in-depth temperature-dependent Raman spectroscopy studies over a wide temperature from 80 to 680 K, the nonlinear frequency shift and linewidth broadening have been observed for both out-of-plane A_1g and in-plane E¹_2g modes, which are associated with the phonon decay mechanisms. For the A_1g mode, the integration of thermal expansion, three- and four-phonon scattering can describe the experimental data well. While for the E¹_2g mode, the analysis including three-phonon and four-phonon processes is enough. Moreover, it is confirmed that the E¹_2g mode has stronger anharmonicity than that of A_1g. The calculations on phonon dispersions and phonon density of states guarantee the viability of possible symmetric and asymmetric phonon scattering channels. Therefore, our temperature-dependent Raman studies and the first-principles calculations jointly shed deep insight into the phonon-phonon interactions in 2H–MoTe₂.

研究 2H–MoTe ₂晶体中的非简谐声子效应至关重要，不仅对于理解其声子介导的热传输，而且对于开发基于 MoTe ₂的高性能功能器件也至关重要。在这里，通过在 80 至 680 K 的宽温度范围内进行深入的温度相关拉曼光谱研究，观察到面外 A _1g和面内 E ¹ _2g模式的非线性频移和线宽展宽，这与声子衰变机制有关。对于A _1g模式，热膨胀、三声子和四声子散射的积分可以很好地描述实验数据。而对于E ¹ _2g模式，包括三声子和四声子过程的分析就足够了。另外，确认了E ¹ _{2g模式比A 1g}模式具有更强的非谐性。声子色散和声子态密度的计算保证了可能的对称和不对称声子散射通道的可行性。因此，我们的温度相关拉曼研究和第一性原理计算共同深入了解了 2H-MoTe ₂中的声子-声子相互作用。