Photoluminescence from Bis-t-Butylbenzoxazolylthiophene Doped Silica Films
WANG Jun-ling1, HE Zhi-qun1*, WANG Yong-sheng1, MU Lin-ping1, YE Shi2, JING Xi-ping2
1. Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044, China 2. The State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
Abstract：Thin nano-porous silica films doped with high concentrations of fluorescent material, 2,5-bis(5-tert-butyl-2-benzoxazolyl)-thiophene (BBOT) were prepared via a sol-gel process. Uniform and bright blue fluorescence was observed. Light emission properties of these organic molecule doped inorganic silica films, i.e., hybrid films, were measured using ultraviolet-visible (UV-Vis) absorption spectroscopy, steady and time-resolved fluorescence spectroscopy as well as optical microscopy. Features of these materials were revealed in this investigation: Firstly, photoluminescence intensity from BBOT doped silica films increased linearly as the concentrations of BBOT increased if the dopant concentration was relatively low and below 6×10-3 mol·L-1; Secondly, no molecular aggregation or phase separation was observed using optical microscopy when the BBOT concentration was below 6×10-3 mol·L-1 in BBOT doped silica films. Thirdly, the fluorescence lifetimes of BBOT in the doped silica films were longer than that in a dilute dioxane solution (1.957 ns), which was contradicted to our general understanding that the fluorescence lifetime may be reduced in a condensed matter due to molecular interactions or quenching. It was further found that the fluorescence lifetime also varied with the gelation conditions. Taking a BBOT concentration of 6×10-3 mol·L-1 for an example, the lifetime of BBOT in doped silica films was about 2.45 ns for a specimen polymerized at 50 ℃; while the lifetime was increased to 3.04 ns for a specimen polymerized at 90 ℃. This work demonstrates no concentration quenching when the BBOT dopant concentrations increased to as high as 6×10-3 mol·L-1 in the silica matrix. In comparison with the changes in time-resolved photoluminescence of BBOT in dioxane solution and that of the BBOT doped nano-porous silica in relation to their concentration dependence and the gelation conditions, it was found that concentration quenching can be effectively suppressed by the nano-porous silica matrix. A stable fluorescent organic-inorganic hybrid material is thus obtained.
王俊玲1,何志群1*,王永生1,穆林平1,叶柿2，荆西平2. 双叔丁基苯并噁唑噻酚在多孔二氧化硅中发光的研究[J]. 光谱学与光谱分析, 2009, 29(07): 1740-1744.
WANG Jun-ling1, HE Zhi-qun1*, WANG Yong-sheng1, MU Lin-ping1, YE Shi2, JING Xi-ping2. Photoluminescence from Bis-t-Butylbenzoxazolylthiophene Doped Silica Films. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2009, 29(07): 1740-1744.
[1] Stracke F, Heupel Ma, Thiel E. Journal of Photochemistry and Photobiology A: Chemistry, 1999, 126(1-3): 51. [2] Galanin M D. Luminescence of Molecules and Crystals, Cambridge: Cambridge Internal Science Pub., 1996. [3] Sakakibara Y, Okutsu S, Enokida T, et al. Applied Physics Letters, 1999, 74(18): 2587. [4] Lutz D R, Nelson K A, Gochanour C R, et al. Chemical Physics, 1981, 58(3): 325. [5] López I Arbeloa. Journal of Photochemistry, 1982, 18(2): 161. [6] López F Arbeloa, Ruiz P Ojeda, López I Arbeloa. Journal of Photochemistry and Photobiology, A: Chemistry, 1988, 45(3): 313. [7] Bera R N, Sakakibara Y, Abe Sh, et al. Synthetic Metals, 2005, 150(1): 9. [8] CAO Duxia, LIU Zhiqiang, ZHAO Guohui, et al. Dyes and Pigments, 2008, 76(1): 118. [9] ZHONG Xian-qiong, YANG Jing-guo, HA Yuan-qing, et al(钟先琼，杨经国，哈元清，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2001, 21(4): 450. [10] WANG Jun-ling, HE Zhi-qun, MAO Hua-xiang, et al. Journal of Luminescence, 2007, 122-123: 268. [11] DONG Wenting, ZHU Congshan. Materials Letters, 2000, 45(6): 336. [12] Johnston C T. Philosophic Degree of Dissertation, University of California, Riverside, CA, 1983. [13] Casalboni M, Senesi R, Prosposito P, et al. Applied Physics Letters, 1997, 70(22): 2969. [14] ZHENG Wei, HUANG Zhi-wei, XIE Shu-sen, et al(郑蔚，黄志伟，谢树森，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 1997, 17(3): 20. [15] CHEN Bi-fang, LIU Tian-fu(陈碧芳，刘天夫). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2006, 26(8): 1513.
