Er3+ excited state absorption and the low fraction of nanocluster-excitable Er3+ in SiOx

Despite the observation by a number of groups of a strong luminescence sensitization effect of erbium ions by excitation exchange from silicon nanoclusters, there is considerable experimental evidence that the fraction of Er ions excited by Si-nc is actually very low for much of the material reported. In this work, we examine the evidence and point out that Er excited state absorption is the likely cause. (c) 2006 American Institute of Physics.