title: Observation of the triplet metastable state of shallow donor pairs in AlN crystals with a negative-U behavior: a high-frequency EPR and ENDOR Study.
abstract: Theoretical predictions about the n-type conductivity in nitride semiconductors are discussed in the light of results of a high-frequency EPR an ENDOR study. It is shown that two types of effective-mass-like, shallow donors with a delocalized wave function exist in unintentionally doped AlN. The experiments demonstrate how the transformation from a shallow donor to a deep (DX) center takes place and how the deep DX center can be reconverted into a shallow donor forming a spin triplet and singlet states.
authors.affiliation: Huygens Laboratory, Leiden University, P.O. Box 9504 2300 RA Leiden, The Netherlands.
authors.forename: Sergei B
authors.initials: SB
authors.lastname: Orlinskii
authors.forename: Jan
authors.initials: J
authors.lastname: Schmidt
authors.forename: Pavel G
authors.initials: PG
authors.lastname: Baranov
authors.forename: Matthias
authors.initials: M
authors.lastname: Bickermann
authors.forename: Boris M
authors.initials: BM
authors.lastname: Epelbaum
authors.forename: Albrecht
authors.initials: A
authors.lastname: Winnacker