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Donor‐Type Tm Centres in ZnS Crystals
Author(s) -
Zimmermann H.,
Boyn R.
Publication year - 1987
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221390219
Subject(s) - excitation , spectral line , impurity , atomic physics , emission spectrum , acceptor , lattice (music) , crystal (programming language) , chemistry , materials science , molecular physics , physics , condensed matter physics , computer science , acoustics , programming language , organic chemistry , quantum mechanics , astronomy
4f—4f excitation and emission spectra involving various intermanifold transitions are determined for two Tm 3+ centres in ZnS crystals by dye‐laser site‐selective measurements at helium temperatures. A crystal‐field analysis together with polarization data indicates that in both cases Tm is located on lattice sites, probably Zn sites. One of the sites (D3) is thought to be in „unperturbed” environment, whereas in the second case (D2) the four nearest‐neighbour atoms are probably replaced by impurity atoms. The excitation and deexcitation mechanisms of the blue 1 G 4 → 3 H 6 emission of these centres are studied by site‐selective broad‐band excitation spectra and kinetical measurements. These studies demonstrate that donor‐acceptor pairs involving the two Tm centres as the donors play an important role in the excitation process. Estimates are given of the relevant pair to 4f state transfer rates.