Understanding how photoexcited electron dynamics depend on electron-electron (e-e) and electron-phonon (e-p) interaction strengths is important for many fields, e.g. ultrafast magnetism, photocatalysis, plasmonics, and others. Here, we report simple expressions that capture the interplay of e-e and e-p interactions on electron distribution relaxation times. We observe a dependence of the dynamics on e-e and e-p interaction strengths that is universal to most metals and is also counterintuitive. While only e-p interactions reduce the total energy stored by excited electrons, the time for energy to leave the electronic subsystem also depends on e-e interaction strengths because e-e interactions increase the number of electrons emitting phonons. The effect of e-e interactions on energy-relaxation is largest in metals with strong e-p interactions. Finally, the time high energy electron states remain occupied depends only on the strength of e-e interactions, even if e-p scattering rates are much greater than e-e scattering rates.

了解光激发的电子动力学如何取决于电子-电子（ee）和电子-声子（ep）的相互作用强度对于许多领域都很重要，例如超快磁性，光催化，等离子体激元等。在这里，我们报告一些简单的表达式，这些表达式捕获ee和ep相互作用在电子分布弛豫时间上的相互作用。我们观察到动力学对ee和ep相互作用强度的依赖性，这对大多数金属来说是普遍的，而且是违反直觉的。虽然只有ep相互作用会减少被激发的电子存储的总能量，但能量离开电子子系统的时间也取决于ee相互作用强度，因为ee相互作用会增加发射声子的电子数量。ee相互作用对能量弛豫的影响在具有强ep相互作用的金属中最大。