There are a few mechanisms of generating hot electrons by optical absorption in metallic nanoparticles. However, I have some questions in my mind....

1. absorption can generate hot electrons, does that also mean the collisions rate increases between electrons to defects and electrons to nuclei?

2.I am wondering under what conditions can electron-electron collision happened.

3. Do collisions always mean heat generation?

4. Can metallic atoms(or metallic ions) be considered as phonons when being stimulated by EM wave?