Under photon excitation, 2D materials experience cascading energy transfer from electrons to optical phonons (OPs) and acoustic phonons (APs). Despite few modeling works, it remains a long‐history open problem to distinguish the OP and AP temperatures, not to mention characterizing their energy coupling factor (G ). Here, the temperatures of longitudinal/transverse optical (LO/TO) phonons, flexural optical (ZO) phonons, and APs are distinguished by constructing steady and nanosecond (ns) interphonon branch energy transport states and simultaneously probing them using nanosecond energy transport state‐resolved Raman spectroscopy. ΔT _{OP −AP} is measured to take more than 30% of the Raman‐probed temperature rise. A breakthrough is made on measuring the intrinsic in‐plane thermal conductivity of suspended nm MoS₂ and MoSe₂ by completely excluding the interphonon cascading energy transfer effect, rewriting the Raman‐based thermal conductivity measurement of 2D materials. G _OP↔AP for MoS₂, MoSe₂, and graphene paper (GP) are characterized. For MoS₂ and MoSe₂, G _OP↔AP is in the order of 10¹⁵ and 10¹⁴ W m⁻³ K⁻¹ and G _ZO↔AP is much smaller than G _LO/TO↔AP. Under ns laser excitation, G _OP↔AP is significantly increased, probably due to the reduced phonon scattering time by the significantly increased hot carrier population. For GP, G _LO/TO↔AP is 0.549 × 10¹⁶ W m⁻³ K⁻¹, agreeing well with the value of 0.41 × 10¹⁶ W m⁻³ K⁻¹ by first‐principles modeling.

中文翻译：

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区分纳米二维材料中光子激发下的光学和声学声子温度及其能量耦合因子。

在光子激发下，二维材料经历从电子到光学声子 (OP) 和声学声子 (AP) 的级联能量转移。尽管建模工作很少，但区分 OP 和 AP 温度仍然是一个长期悬而未决的问题，更不用说表征它们的能量耦合因子 ( G )。在这里，通过构建稳定和纳秒（ns）间声子分支能量传输状态并同时使用纳秒能量传输状态探测它们来区分纵向/横向光学（LO/TO）声子、弯曲光学（ZO）声子和AP的温度。解析拉曼光谱。测量得出的Δ TOP _-AP占拉曼探测温升的 30% 以上。通过完全排除间声子级联能量传递效应，在测量悬浮纳米MoS ₂和MoSe _{2的本征面内热导率方面取得了突破，重写了基于拉曼的二维材料热导率测量。}对 MoS ₂、MoSe ₂和石墨烯纸 (GP)的G _{OP↔AP进行了表征。}对于MoS ₂和MoSe ₂，G _{OP↔AP 的}量级为10 ¹⁵和10 ¹⁴ W m ^-3 K ^-1，并且G _ZO↔AP比G _LO/TO↔AP小得多。在纳秒激光激发下，G _OP↔AP显着增加，可能是由于热载流子数量显着增加而减少了声子散射时间。对于GP，G _LO/TO↔AP为0.549 × 10 ¹⁶ W m ^-3 K ^-1 ，与第一原理建模得到的值0.41 × 10 ¹⁶ W m ^-3 K ^{-1非常吻合。}