Abstract
A study of transient optical absorption of the ADP (NH4H2PO4) and KDP (KH2PO4) nonlinear crystals in the visible and UV spectral regions is reported. Measurements made by absorption optical spectroscopy with nanosecond-time resolution established that the transient optical absorption (TOA) of these crystals originates from optical transitions in the hole A and B radicals and the optical-density relaxation kinetics is rate-controlled by interdefect tunneling recombination, which involves these hole centers and the electronic H0 centers representing neutral hydrogen atoms. At 290 K, hole polarons and the H0 centers undergo thermally stimulated migration, which is not accompanied by carrier ejection into the conduction or valence band. The slow components of the TOA kinetics with characteristic times from a few tens of milliseconds to a few seconds can be assigned to diffusion-controlled annihilation of hydrogen vacancies associated with impurity or structural defects.
Original language | English |
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Pages (from-to) | 880-887 |
Number of pages | 8 |
Journal | Physics of the Solid State |
Volume | 44 |
Issue number | 5 |
DOIs | |
Publication status | Published - 1 May 2002 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics