In semiconductor devices there are two types of charge carriers: electrons and holes. In N-type doped semiconductor the majority charge carriers are electrons and the minority charge carriers are holes. In P-type doped semiconductor the majority charge carriers are holes and the minority charge carriers are electrons.

Some kinds of semiconductor devices operate using minority charge carriers in part(s) of their structure. The common bipolar junction transistor is one of these, they are sensitive to a phenomenon called thermal runaway because additional minority carriers are produced as temperature increases. (field effect transistors however operate using only majority carriers and are thus not sensitive to thermal runaway)