Liquid-phase epitaxy from an Si-In-Er solution at an average temperature of
950 degrees C has been used to grow 2- 4 mu m thick epilayers of erbium-do
ped silicon onto CZ and FZ silicon substrates in an oxygen-free hydrogen at
mosphere. Most of the samples grown on CZ substrates presented detectable,
but feeble photoluminescence at 2. K in the spectral range of emission of t
he Er3+ manifold at 0.8 eV. However, some of the samples presented intense
photoluminescence characterized by two bands at 0.807 (at 10 K) and 0.873 e
V, of which the first falls almost at the same energy of the Er3+ line, but
whose intensity presents a quite remarkable persistence up to 250 Ii. From
the energy position of the two bands, from their temperature dependence an
d from the levels found by deep level transient spectroscopy measurements,
associated to TEM examinations, it was possible to attribute these bands, l
abelled D1 and D2, to dislocation luminescence. It will be shown in this pa
per that the presence of erbium enhances the D1 luminescence, possibly due
to the fact that in these samples erbium is gettered at dislocations in an
Er-O local configuration, as it results from EXAFS measurements. Apparently
, also, a competition occurs with the Er-induced radiative recombination at
dislocations, which is a fast process, and the indirect excitation of the
Er manifold, which is the predominant process in dislocation-free materials
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