Structure And Photoluminescence Of Rare Earth Ions Doped Al₂O₃ With A Combination Of SiO₂ And P₂O₅

The photoluminescence (PL) at the wavelength of 1.53 μm was limited by -OH quenching for the Er³⁺ doped materials prepared by a sol-gel method. In this paper, by mixing SiO₂ and P₂O₅, the - OH was removed from Er³⁺ doped Al₂O₃ prepared by the non-aqueous sol-gel method The 0.1 mol% Er³⁺-doped SiO₂-Al₂O₃ powders have been prepared by mixing SiO₂ sol and Al₂O₃ sol. The results show that the phase transition of γ→θ and θ→α was suppressed by adding 5 mol% SiO₂ into the Er³⁺-doped Al₂O₃. For the 0.1 mol% Er³⁺-doped Al₂O₃ powders at the sintering temperature of 900 ℃, the broadband PL spectrum centered at 1.53 μm in the range from 1.47 μm to 1.63 μm was obtained with the full width at half maximum of 56 nm, and the splitting PL spectra appeared at the sintering temperature of 1000-1200 ℃. For the 0.1 mol% Er³⁺-doped Al₂O₃-SiO₂ powders, the PL spectra are of a single broadband centered at 1.53 μm even at the sintering temperature of up to 1200 ℃, and compared with the PL spectra of the Al₂O₃ powders without mixing SiO₂ at the sintering temperature of 900 ℃, the PL intensity increases by a factor of one order in magnitude, and the fluoresce lifetime increases to 4.29 ms, because -OH group in the Al₂O₃-SiO₂ powders has been removed completely.1.0 mol% Er³⁺-doped xP₂O₅-(1-x)Al₂O₃ powders have been prepared by introducing CH₃CH₂O)₃P=O into the Al₂O₃ sol. With the P₂O₅ content increasing, the -OH was removed gradually and the PL intensity was increased evidently. The -OH was removed completely when the P₂O₅ content was reached to 30 mol%, the fluorescence lifetime was increased from 1.32 to 2.42 ms, and the PL intensity was increased by about two orders, compared with that of the powders without P₂O₅ introduction. The homogeneous, smooth and crack-free Er³⁺/Yb³⁺ codoped P₂O₅-Al₂O₃ film was obtained on thermally oxidized SiO₂/Si(100) substrates by sol-gel dip-coating technology through 20 coating cycles. The film was of γ-Al₂O nanometer polycrystalline, and the fusiform crystal particles about 30-80 nm were observed by XTEM, which were paralleled to the film. The PL intensity of the film was...