【作者】 邓立儿； 富鸣； 王永生； 何大伟；

【Author】 Deng Lier~(*1) Fu Ming~2 Wang Yongsheng~2 He Dawei~2 (1 School of Optoelectronic Engineering,Xi’an Technological University,Xi’an,710032,China) (2 Key Laboratory of Luminescence and Optical Information,Institute of Optoelectronic Technology, Beijing Jiaotong University,100044,Beijing,China)

【机构】 西安工业大学光电学院； 北京交通大学光电子技术研究所发光与光信息技术教育部重点实验室；

【摘要】 光子晶体中介质的周期分布会对置入其中的发光分子的自发发射光谱产生调制,稀土元素不但可以窄带发射,而且具有较高的荧光效率,因而以稀土Tb³⁺作为探针,研究TiO₂反蛋白石结构的光子带隙对其自发发射光谱的影响。样品制备大致分为三步:1、将直径为410nm的聚苯乙烯（PS）胶体微球以自组装方法制备得到PS胶体晶体模板。2、使用溶胶凝胶法制备TiO₂溶胶。3、将TiO₂溶胶分别滴加到PS胶体晶体模板和载玻片上,放入加热炉中升温至450℃烧结4小时,得到TiO₂的反蛋白石结构薄膜和TiO₂的无序多孔结构薄膜。4、制备一定浓度的醋酸铽溶液。5、将醋酸铽的水溶液滴加到TiO₂的反蛋白石结构薄膜上,80℃下水分蒸干后制得样品A;同样将醋酸铽的水溶液滴加到TiO₂的无序多孔结构薄膜上,80℃下水分蒸干后制得样品B（参考样品）。实验结果表明,相对于样品B,样品A中Tb³⁺的发射光谱在540nm处的发光强度明显降低,而在484nm处的发光强度有所增大,其余两个峰位的发光强度基本一致。这是由于540nm处的发射峰正好位于样品A反蛋白石结构的光子禁带中心,而484nm处的发射峰位于光子带隙的短波带边。光子禁带处的光子态密度较小,带边处光子态密度较大,从而使置于其中的发射峰受到相应的抑制和增强。更多还原

【Abstract】 Photonic crystals have turned out to be a promising tool to control spontaneous emission.Rare earth complexes show narrow-line emission and high fluorescence efficiency and can be used as a luminescent probe to study the PBG effect on spontaneous emission.The samples were prepared as follows. The opal templates were assembled by vertical deposition of silica spheres 410 nanometers in diameter.TiO₂ precursor solution prepared with sol-gel were used to infiltrate into the voids of the opal templates. Meanwhile.TiO₂ precursor solution deposited on a plain glass substrate were prepared as a reference sample. Then the opals and reference sample were calcined at 450℃for 4 h in an air furnace.The Tb³⁺doped TiO₂ inverse opals were prepared by dropping sodium terbium solution and dried in air as sample A,and reference sample dropping with sodium terbium solution was denoted as sample B.Compared with the sample B,the photoluminescence from Tb³⁺doped TiO₂ inverse opal photonic crystal was suppressed at 540nm and enhanced at 484nm due to the presence of the photonic band gap.Either suppression or enhancement depends on the difference of photon density of states between emission band and the stop-band.更多还原