Er 3+  ions–Si nanocrystals interactions and their effects on the luminescence properties

Abstract

A detailed investigation on the interaction mechanisms between Er ions and Si nanocrystals (nc) is reported. Silicon nc were produced by high-temperature annealing of substoichiometric SiOx thin films grown by plasma-enhanced chemical vapor deposition. Subsequently, some of the samples were implanted by Er. These samples show intense room-temperature luminescence at both 1.54 and 0.98 μm. High-resolution luminescence spectra of Er-implanted Si nc suggest that the emitting Er ions are located in the SiO2 or at the Si nc/SiO2 interface. The pump-power dependence and the time decay of the 1.54 μm emission in Si nc with different Er contents have evidenced the presence of several nonradiative decay processes due to Er–Er and Er–Si nc interactions. Moreover, the number of Er ions per Si nc is shown to be a quite critical parameter in determining the final properties of the overall system.