The occurrence of a very efficient non-resonant energy transfer process forming ultrasmall Au–Ag nanoalloy clusters and Er3+ ions is investigated in silica. The enhancement of the room temperature Er3+ emission efficiency by an order of magnitude is achieved by coupling rare-earth ions to molecule-like (AuxAg1x)N alloy nanoclusters with N = 10–15 atoms and x = 0.6 obtained by optimized sequential ion implantation on Er-implanted silica. For comparison, AuN nanoclusters obtained by the same approach and with the same size and numerical density showed an enhancement by only a factor of 2 with respect to pure Er emission, demonstrating the beneficial effect of using nanoalloyed clusters. The temperature evolution of the energy transfer process is investigated by photoluminescence and exhibits a maximum efficiency at about 600 °C, where the clusters reach the optimal size and the silica matrix completely recovers the implantation damage. The nanoalloy cluster composition and size have been studied by EXAFS analysis, which indicated a stronger Ag–O interaction with respect to the Au–O one and a preferential location of the Ag atoms at the nanoalloy cluster surface.

Au–Ag nanoalloy molecule-like clusters for enhanced quantum efficiency emission of Er3+ ions in silica

CESCA, TIZIANA;KALINIC, BORIS;MICHIELI, NICCOLO' TOMASO;MAURIZIO, CHIARA;SCIAN, CARLO;MAZZOLDI, PAOLO;MATTEI, GIOVANNI
2015

Abstract

The occurrence of a very efficient non-resonant energy transfer process forming ultrasmall Au–Ag nanoalloy clusters and Er3+ ions is investigated in silica. The enhancement of the room temperature Er3+ emission efficiency by an order of magnitude is achieved by coupling rare-earth ions to molecule-like (AuxAg1x)N alloy nanoclusters with N = 10–15 atoms and x = 0.6 obtained by optimized sequential ion implantation on Er-implanted silica. For comparison, AuN nanoclusters obtained by the same approach and with the same size and numerical density showed an enhancement by only a factor of 2 with respect to pure Er emission, demonstrating the beneficial effect of using nanoalloyed clusters. The temperature evolution of the energy transfer process is investigated by photoluminescence and exhibits a maximum efficiency at about 600 °C, where the clusters reach the optimal size and the silica matrix completely recovers the implantation damage. The nanoalloy cluster composition and size have been studied by EXAFS analysis, which indicated a stronger Ag–O interaction with respect to the Au–O one and a preferential location of the Ag atoms at the nanoalloy cluster surface.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/3156459
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