Non-equilibrium phonons have been discussed for almost six decades. Here, the nature of the longitudinal optical mode, particularly in polar materials, is discussed along with its lifetime and bottleneck occurrences. The history of non-equilibrium phonons is discussed along with their generation by the relaxation of hot carriers. The role of inter-valley scattering and phonon lifetime is introduced along with the concept of a phonon bottleneck. Various methods of lifetime measurement are introduced. Measurements of the lifetime in a variety of semiconductor materials is reviewed and a possible scaling behavior discussed.

中文翻译：

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非平衡纵向光学声子及其寿命

非平衡声子已经讨论了近 60 年。在这里，纵向光学模式的性质，特别是在极性材料中，与其寿命和瓶颈现象一起讨论。非平衡声子的历史与它们通过热载流子弛豫的产生一起讨论。谷间散射和声子寿命的作用与声子瓶颈的概念一起介绍。介绍了各种寿命测量方法。回顾了各种半导体材料的寿命测量，并讨论了可能的缩放行为。