ISSN:
1077-3118
Source:
AIP Digital Archive
Topics:
Physics
Notes:
A new, very efficient excitation mechanism of Yb intrashell 4f-4f emission in ZnS is reported. We show that the energy transfer from donor-acceptor pairs to Yb sites leads to Yb ionization (Yb3+⇒Yb2+), followed by capture of ionized carriers via the Yb3+ external excited state (bound exciton state), an energy transfer to the Yb3+ 4f shell, and Yb3+ 4f-4f radiative recombination. Since three centers (donor, acceptor, and Yb) participate in the energy transfer process in which Yb is first ionized, the above excitation mechanism is of three-center Auger transition nature. A similar excitation mechanism is expected for Eu, Sm, and Tm in ZnS, i.e., for these rare earth (RE) ions which can change their charge state from 3+ to 2+ in this lattice. For wider band-gap sulfides, such as CaS or SrS, this mechanism can be of importance also for other REs, such as, for example, Pr, Dy, and Er.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.103572
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