Energy transfer process between Eu3+ and wide-band-gap SnO2 nanocrystals in silica films studied by photoluminescence excitation and time-resolved photoluminescence techniques

Abstract

Eu3+ ions embedded in silica thin films co-doped with SnO2 nanocrystals were fabricated by sol–gel and spin-coating methods. SnO2 nanocrystals with controllable sizes were synthesized through precisely controlling the Sn concentrations. The influences of doping and annealing conditions on the photoluminescence intensity from SnO2 nanocrystals are systematically investigated. The effective energy transfer from the defect states of SnO2 nanocrystals to nearby Eu3+ ions has revealed by the selective photoluminescence excitation spectra. The efficiency of the Forster resonance energy transfer is evaluated by the time-resolved photoluminescence measurements, which is about 29.1 % based on the lifetime tests of the SnO2 emission.