The paper presents the results of a study of the formation and decay of lattice defects in nonlinear optical crystals of NH 4H 2PO 4 (ADP), KH 2PO 4 (KDP), Li 2B 4O 7 (LTB) and LiB 3O 5 (LBO) with a sublattice of mobile hydrogen (ADP, KDP) and lithium (LTB, LBO) cations. By means of the luminescent and absorption optical spectroscopy with (the) a nanosecond time resolution under excitation with an electron beam, it was revealed that the optical absorption of these crystals in the visible and UV spectral ranges is produced by optical hole-transitions from the local defect level to the valence band states. The valence band density of the states determines the optical absorption spectral profile, and the relaxation kinetics is rated by the interdefect radiationless tunnel recombination between the trapped hole center and the H 0 and Li 0 electron trapped centers. At 290 K, the H 0 and Li 0 centers are subject to thermally stimulated migration. All manifestations of a radiative recombination observed in these crystals are accounted for by the involvement of additional electronic and hole centers of a different nature in the recombination process.
|Название основной публикации||Physica Status Solidi C: Conferences|
|Состояние||Опубликовано - 2005|
ASJC Scopus subject areas
- Condensed Matter Physics