We discuss the use of rate equations to analyze the sensitization of erbium luminescence by silicon nanoclusters. In applying the general form of second-order coupled rate-equations to the Si nanocluster-erbium system, we find that the photoluminescence dynamics cannot be described using a simple rate equation model. Both rise and fall times exhibit a stretched exponential behavior, which we propose arises from a combination of a strongly distance-dependent nanocluster-erbium interaction, along with the finite size distribution and indirect band gap of the silicon nanoclusters. Furthermore, the low fraction of erbium ions that can be excited nonresonantly is a result of the small number of ions coupled to nanoclusters. © 2008 The American Physical Society.
|Titolo:||Generalized rate-equation analysis of excitation exchange between silicon nanoclusters and erbium ions|
|Autori interni:||OTON NIETO, CLAUDIO JOSE|
|Data di pubblicazione:||2008|
|Rivista:||PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS|
|Appare nelle tipologie:||1.1 Articolo su Rivista/Article|