Photoluminescence in Er3+/Yb3+-doped silica-titania inverse opal structures
Photoluminescence in Er3+/Yb3+-doped silica-titania inverse opal structures
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DOI：
10.1007/s10971-010-2212-y
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发表时间：
2010-07-01
影响因子：
2.5
通讯作者：
Bhaktha, Shivakiran
中科院分区：
文献类型：
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作者：
Goncalves, M. Clara;Fortes, Luis M.;Bhaktha, Shivakiran
从沉积聚苯乙烯微球开始，采用溶胶-凝胶法合成了三维反蛋白石（IO）结构，研究了Er 3+的近红外光致发光（PL）和Yb 3 + → Er 3+的能量转移（ET）现象（235 nm和460 nm直径）直接蛋白石模板通过对流自组装，然后用Er 3 +/Yb 3+掺杂的二氧化硅渗透间隙，二氧化钛和二氧化硅-二氧化钛溶胶以及聚合物模板材料的热移除。通过适当的衬底处理，加上模板沉积过程中的温度和湿度控制，优化了IO的结晶质量。通过场发射扫描电子显微镜和可见近红外反射光谱研究了3-D蛋白石和IO结构的结构和光学性质，以评估微观结构和所获得的光子学性质之间的关系。光子带隙已被证明在反射光谱中的相应的阻带。相对于没有光子晶体结构的类似基质沉积物，在大多数IOs中，在类似于1.5 μ m处的Er 3 + I-4（13/2）-> I-4（15/2）跃迁的形状和强度被修改，特别是在纯二氧化硅和二氧化钛IOs的情况下，其中PL峰变窄并增强。在此阶段不可能在IO结构中检测到Yb 3 + -> Er 3 + ET现象。
Er3+ photoluminescence (PL) and Yb3+ -> Er3+ energy transfer (ET) phenomena in the near infrared (NIR) have been studied in three-dimensional (3-D) inverse opal (IO) structures synthesized by a colloidal/sol-gel route, starting with the deposition of polystyrene microsphere (235 nm and 460 nm diameter) direct opal templates by convective self-assembly, followed by infiltration of the interstices with Er3+/Yb3+-doped silica, titania and silica-titania sols and heat-removal of the polymeric template material. The crystalline quality of the IOs has been optimized through suitable substrate treatments, plus the control of temperature and humidity during deposition of the templates. The structural and optical properties of the 3-D opal and IO structures have been studied by field emission scanning electron microscopy and visible-NIR reflection spectroscopy, in order to assess the relationship between microstructure and the photonic properties obtained. Photonic bandgaps have been evidenced by the corresponding stop bands in the reflection spectra. The shape and the intensity of the Er3+ I-4(13/2) -> I-4(15/2) transition at similar to 1.5 mu m were modified in most IOs relatively to similar matrix deposits without a photonic crystal structure, particularly in the case of pure silica and titania IOs, where the PL peak narrowed and intensified. It was not possible at this stage to detect Yb3+ -> Er3+ ET phenomena in the IOs structures.