So yeah, I'm doing my dissertation for my final year of a BA in History and while I'm fairly set as far as devouring recent (and not so recent) biographies of Napoleon and histories of the Empire, I'm embarrassingly short on knowledge of ideal primary sources (obviously I know about Benjamin Constant, Madame de Stael, etc. but couldn't honestly tell you how accessible the French texts are). Any suggestions/condemnations/rants about my incompetence as a a student would be welcome :)
Well, the problem is that I think you're doing this in the wrong way. When it comes to the concept of an Enlightened Despot, primary sources such as diaries and journals can only do so much, give the opinion of the subject. However the true Enlightened Monarch shows themselves in their actions, so you might want to look at things that would show Napoleon as an Enlightened Despot, such as laws or personal decisions and possibly compare that to those whom we do consider the Enlightened Despot, such as Catherine the Great, Frederick Wilhelm III, and Joseph II.
However, I wouldn't argue that Napoleon was truly an Enlightened Despot which I have discussed here.