【作者】 王辉；

【导师】 雷明凯；

【作者基本信息】 大连理工大学 ， 材料表面工程， 2006， 硕士

【摘要】 采用非水性sol-gel法制备Er³⁺-Y³⁺共掺杂Al₂O₃粉末,选取0.1和1mol%两种Er³⁺掺杂浓度,系统地研究了Y³⁺、Er³⁺浓度比例范围为（1-10）∶1的Y³⁺共掺杂对900和1000℃烧结的掺Er³⁺¹∶Al₂O₃结构及其光致发光（PL）特性的影响。 900和1000℃烧结的掺0.1和1mol%Er³⁺∶Al₂O₃粉末,其相结构均为具有非晶化特征的γ和θ相混合结构。其中,掺0.1mol%Er³⁺粉末,随0.1-1mol%Y³⁺浓度增加其γ和θ相非晶化趋势更加显著。900和1000℃烧结的掺1.mol%Er³⁺浓度粉末,其γ和θ相结构的非晶化趋势分别随1-10和1-5mol%Y³⁺的共掺杂浓度增加而更加严重;1000℃烧结时,10mol%Y³⁺共掺杂粉末γ相消失,具有立方结构的（Er,Y）₃Al₅O₁₂化合物析出。傅立叶变换红外光谱（FTIR）测量表明,相同温度烧结的不同比例Y³⁺共掺杂的掺Er³⁺∶Al₂O₃粉末中,O-H基团特征吸收峰波段范围(4000-2500cm^-1)和吸收峰强度均无明显差异,说明Y³⁺共掺杂对其振动频率和含量无明显影响。 980nm激光泵浦下,掺Er³⁺∶Al₂O₃粉末具有峰值波长在1.53μm、660nm（红光）和545、523nm（绿光）附近的PL特性,其中前者为斯托克斯（Stokes）发光,后者红光和绿光为上转换发光。Y³⁺掺杂对其PL强度具有明显影响。一方面Y³⁺共掺杂降低了掺Er³⁺∶Al₂O₃粉末基体的声子能量,导致Er³⁺⁴I_11/2能级寿命增加,其Stokes发光和红光强度下降,绿光强度提高,红、绿光强度比随之降低:另一方面Y³⁺共掺杂可有效提高Er³⁺的分散度,减小Er³⁺光致发光的浓度猝灭效应,提高掺杂Er³⁺∶Al₂O₃粉末的PL强度。掺Er³⁺浓度为0.1mol%时,因其浓度猝灭效应较小,Y³⁺共掺杂主要体现降低声子能量这一效应,其PL强度随Y³⁺共掺杂发生相应变化;掺Er³⁺浓度为1mol%时,Y³⁺共掺杂既降低了基体声子能量,又减小了Er³⁺浓度猝灭,使得900和1000℃烧结粉末的Stokes发光和上转换发光强度均随1-10mol%Y（3+）共掺杂浓度的增加而增大,同时红、绿光强度比随Y³⁺浓度增加而降低。Y³⁺共掺杂对掺Er³⁺∶Al₂O₃粉末Stokes光谱半高宽（FWHM）亦有影响。掺Er³⁺浓度为0.1mol%时,900℃烧结粉末Stokes光谱的FWHM随Y³⁺共掺杂无明显变化,1000℃烧结粉末的FWHM随Y³⁺浓度增加有所增大;掺Er³⁺浓度为1mol%时,除1000℃烧结的10mol%Y³⁺共掺杂粉末,其光谱FWHM降低外,900和1000℃烧结粉末的光谱FWHM均随Y³⁺浓度增加而增大。更多还原

【Abstract】 The 0.1 and 1 mol% Er³+ doped Al₂O₃ powders by Y³+ codoping with the molar ratio of （0-10） : 1 for Y³+ and Er³+ at the sintering temperature of 900 and 1000℃ were prepared by the non-aqueous sol-gel method. The effects of Y³+ codoping on the structure and photoluminescence properties of the powders were investigated.The 0.1 and 1 mol% Er³+-doped Al₂O₃ powders sintered at 900 and 1000 ℃ are of the mixture of γ and θ phases, which are both non-crystallization. The 0.1-1 mol% Y³+ codoping promotes the non-crystallization of the γ and θ phases for the 0.1 mol% Er³+-doped Al₂O₃ powders. The non-crystallization is also promoted by the 1-10 and 1-5 mol% Y³+ codoping for the 1 mol% Er³+-doped powders sintered at 900 and 1000 ℃ respectively, while the γ phases disappeares and the （Er,Y）₃Al₅O₁2 compound appears for the 1 mol% Er³+-doped powders at the sintering temperature of 1000 ℃ by 10 mol% Y³+ codoping. The FTIR spectra shows that the wavenumber range and the intensity of the absorption peak for O-H have no evident changes for the powders by Y³+ codoping sintered at same temperature, indicating that Y³+ codoping has no influence on the oscillation frequency and content of the O-H for the Er³+-doped Al₂O₃ powders.The Er³+-doped Al₂O₃ powders are characteristic of the photoluminescence （PL） spectra peaked at 1.53 urn, 660 nm （red emission）, 545 and 523 nm （green emission） pumping by the laser with wavelength of 980 nm, and the emission peaked at 1.53μm is of stokes emission while the other two are of up-conversion emission. Y³+ codoping has evident effects on the PL properties of the powers. On the one hand, Y³+ codoping decreases the phone energy of the powders and increases the lifetime of the ⁴I₁1/2 level for Er³+, leading to a decrease in the intensity of Stokes emission and red emission as well as a increase in the intensity of green emssion and a decrease in the intensity ratio for the red emission and green emission. On the other hand, Y³+ codoping effectively decreases the concentration quenching effect of the Er³+, leading to an increase in the intensity of both Stokes emission and upconversion emission. For the 0.1 mol% Er³+-doped Al₂O₃ powders, the concentration quenching has small effect on its PL, and the Y³+ codoping only decreases its phone energy with a corresponding changes in its PL intensity. For the 1 mol% Er³+-doped powders, Y³+ codoping decreases both the phone energy and the Er³+ concentration quenching, leading to an increase in both the Stokesemission and the upconversion emission with a decrease in the intensity ratio for green emssion and red emission. Y3+ codoping also influence the full width at half maximum （FWHM） of the PL spectrum peaked at 1.53 um for the Er3+-doped AI2O3 powders. For the 0.1 mol% Er3+-doped powders sintered at 900 °C, the FWHM of the PL spectra has no evident change with Y3+ codoping, for that sintered at 1000 °C, the FWHM increases slightly by Y3+ codoping. The FWHM of the PL spectra for the 1 mol% Er3+-doped AI2O3 powders sintered at 900 and 1000 °C both increase with the increase of the Y3+ codoping concentration, except a decrease in the FWHM of the spectrum for the powders sintered at 1000 °C by 10 mol%Y3+codoping.更多还原