Physical characteristics and infrared fluorescence properties of sol–gel derived Er3+–Yb3+ codoped TiO2

{Er}^{3+} - {Yb}^{3+}

codoped

{TiO}_{2}

films were prepared on fused silica by sol–gel processes. The

{Yb}^{3+}

codoping effect on the physical characteristics and ∼1.54 μm photoluminescence (PL) properties of

{Er}^{3+}

-doped

{TiO}_{2}

films was investigated. Maximum ∼1.54 μm PL intensity occurs in

{Er}^{3+}

(5 mol %)– {Yb}^{3+} (30 mol %)

codoped

{TiO}_{2}

samples annealed at 700 °C. However, when the concentration of

{Yb}^{3+}

ions is more than 30 mol %, the back energy transfer effect from

{Er}^{3+}

{Yb}^{3+}

will deteriorate the ∼1.54 μm PL efficiency. Extended x-ray absorption fine structure measurements show that the average spatial distance between

{Er}^{3+}

ions is slightly decreased due to the partial substitution of

{Yb}^{3+}

for

{Er}^{3+}

ions in the local structure. The

{Yb}^{3+}

ion in the

{Er}^{3+} - {Yb}^{3+}

codoped

{TiO}_{2}

samples not only plays the role of disperser but is also a sensitizer of the

{Er}^{3+}

ion. This dual effect leads to larger PL intensity in the

{Er}^{3+} - {Yb}^{3+}

codoped

{TiO}_{2}

system in comparison with

{Er}^{3+} - Y^{3+}

codoped

{TiO}_{2}

samples. Compared with

{SiO}_{2}

films with

{Er}^{3+}

(5 mol %)– {Yb}^{3+}

(30 mol %) codoped and annealed at optimal temperature of 985 °C, the

{Er}^{3+} - {Yb}^{3+}

codoped

{TiO}_{2}

film obtains better PL properties at lower annealing temperature.

This publication has 29 references indexed in Scilit: