Patent ID: 7786550

Claim:
A p-type semiconductor comprising a plurality of elements, one of the elements being a localized band formation element, the localized band formation element being isovalent with at least one other of the elements of the p-type semiconductor and having a smaller electronegativity than an electronegativity of the at least one other element, wherein another of the elements is an acceptor element, the acceptor element having fewer valence electrons than valence electrons of at least one other of the elements of the p-type semiconductor, an amount of the localized band formation element in the p-type semiconductor is larger than an amount of the acceptor element in the p-type semiconductor, the acceptor element has a lower energy level than a top of an energy band of the localized band formation element, the acceptor element and the localized band formation element are distributed uniformly, an amount of the localized band formation element in the p-type semiconductor is 2 atom % or less, the p-type semiconductor is a compound semiconductor, the compound semiconductor is a nitride semiconductor, and the nitride semiconductor is a compound semiconductor which has at least one Group III element including boron and at least one Group V element including nitrogen.