Fluorescence enhancement and structural development of sol-gel derived Er3+-doped SiO2 by yttrium codoping

Er3+-Y3+ codoped SiO2 powdered bulks were prepared by a sol-gel process. The effect of Y3+ codoping on the fluorescence properties and structural development of Er3+-doped SiO2 is investigated. The maximum similar to1.54 mum photoluminescence (PL) intensity occurs in the sample with Er3+ (10 mol%)-Y3+ (50 mol%) codoped and annealed at 985 degreesC. This can be attributed to the competition between the content of hydroxy groups and Er site symmetry. Improvement of optimum PL properties due to Y3+ codoping by a factor of similar to20 for intensity and 1.8 for the full width at half maximum (57 nm) was obtained in comparison with the Er3+-doped SiO2 system. Extended X-ray absorption fine structure analysis shows that the local chemical environment of Er3+ ions in the Er3+-Y3+ codoped SiO2 is similar to that in Er2O3. The average spatial distance between Er3+ ions is enlarged due to a partial substitution of Y3+ for Er3+ ions in the Er2O3-like local structure, which results in a reduction of the concentration quenching effect.