hide
Free keywords:
-
Abstract:
Abstract. A new near-infrared luminescence band due to internal transitions of tungsten
in ZnSe crystals is described. It is characterized by a weak zero-phonon line (ZPL) at v = D 10 700 cm−1 (λ = 934:6 nm) and 40 partially strong phonon satellites which reveal the presence of quasilocalized modes with energies of 33, 77, and 100 cm−1. A magnetic field does not split the ground state, indicating that this is a 1A1 state of a low-spin configuration of
W2C .5d4/. The lifetime of the excited state is .47 ± 2/ µs. Intense absorption bands around 12 000 and 13 000 cm−1 dominating the PLE spectrum are assigned to internal W transitions. Under excitation with 9400 cm−1 (1.064 µm) a further emission appears starting at 6655 cm−1
with a weak ZPL followed by several stronger phonon lines. The distances between these peaks
coincide in some cases with the quasilocalized modes of the former emission. Therefore, this
luminescence is probably also related to tungsten centres.
