From a quick Google, Graf Zeppelin was the only carrier the Third Reich came close to finishing, but they neglected completing that ship anyway from 1938. Why?
I'm under the impression that the Luftwaffe was quite a powerful force in the Wehrmacht because it was new and so staffed largely with loyalists. Did this encourage the government towards projecting air power on the sea? If so, why didn't they?
You will likely find this thread with responses from /u/the_chieftain_wg and /u/kieslowskifan to be of interest for you!