Abstract Here, we report an analysis of the double-resonance (DR) Raman bands in bilayer tungsten diselenide (WSe2) as a function of temperature and for different laser excitation energies. Using different laser excitation energies, we verify that the double-resonance Raman is strongly enhanced in the lower laser excitation energy due to the resonance with the B exciton. Using two different laser excitation energies (1.96 eV and 2.41 eV) and changing the temperature in the range from 293 to 593 K, we determine that all mode wavenumbers decrease linearly as the temperature increases. However, the double-resonant band decay is two orders of magnitude faster than the first-order modes. This study in double-resonance Raman sheds a further insight of the excitonic state of bilayer WSe2 and shows that dispersive signature arises in terms of effects beyond the harmonic approximation, mainly electron-phonon intervalley interactions and anharmonicities.

中文翻译：

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双层中双共振拉曼带的温度依赖性 - WSe2

摘要 在这里，我们报告了双层二硒化钨 (WSe2) 中的双共振 (DR) 拉曼谱带作为温度和不同激光激发能量的函数的分析。使用不同的激光激发能量，我们验证了由于与 B 激子的共振，双共振拉曼在较低的激光激发能量中得到强烈增强。使用两种不同的激光激发能量（1.96 eV 和 2.41 eV）并在 293 到 593 K 的范围内改变温度，我们确定所有模式波数随着温度的升高而线性下降。然而，双谐振带衰减比一阶模式快两个数量级。