Effects of yttrium codoping on photoluminescence of erbium-doped TiO2 films

Abstract

Er3+-Y3+ codoped TiO2 films were prepared on a fused silica substrate by the sol-gel process. The effect of Y3+ codoping on the similar to1.54 mum photoluminescence (PL) properties of Er3+-doped TiO2 films are investigated. Enhancement of PL properties due to Y3+ codoping by a factor of 10 for intensity and of 1.5 for the full width at half maximum in comparison with the Er3+-Al3+ codoped SiO2 system has been observed in the film annealed at Er3+:Y3+:Ti4+=5:30(similar to 50):100. Extended x-ray absorption fine structure measurements show that the local chemical environment of Er3+ ions in the Er3+-Y3+ codoped TiO2 films is similar to that in Er2O3. The average spatial distance between Er3+ ions is enlarged due to the partial substitution of Y3+ for Er3+ ions in the Er2O3-like local structure. It is believed that the more intense PL emission of the Er3+-Y3+ codoped TiO2 films can be attributed to the better dispersion and distorted local structure of Er3+ ions in the TiO2 host matrix by yttrium codoping. (C) 2001 American Institute of Physics.