Abstract
We present a self-consistent theory of the steady-state electron distribution in metals under continuous-wave illumination which treats, for the first time, both thermal and non-thermal effects on the same footing. We show that the number of non-thermal electrons (i.e., the deviation from thermal equilibrium) is very small, so that the power fraction that ends up generating these non-thermal electrons is many orders of magnitude smaller than the fraction of power that leads to regular heating.
Using this theory, we re-examine the exciting claims on the possibility to enhance chemical reactions with these non-thermal (i.e., ''hot'') electrons. We identify a series of rather astounding errors in the temperature measurements in some of the most famous papers on the topic which led their authors to under-estimate regular heating effects. As an alternative, we show that a very simple 19th century theory, based on just simple heating, can explain the published experimental data with excellent accuracy.