采用溶胶-凝胶法制备了1mol%、3mol%、5mol%、8mol% Ho3+掺杂的Ba0.65Sr0.35 TiO3薄膜, 研究了薄膜的表面AFM、XRD谱、光学透射谱和光致发光谱. 结果表明: Ho3+浓度从1mol%增加到8mol%时, BST薄膜的晶格常数先增大后减小; 位于615、650和750nm处的发光, 分别对应5F3→5F7、5F5→5F8和5S2、5F4→5F 的跃迁, 发光谱和5S2, 5F4的寿命谱分析表明, 在Ho3+浓度为3mol%时三个发光带强度均最大. 并分析了Ho3+与Ba2+/Sr2+/Ti4+的离子位置替代机制及交叉弛豫机制.
Barium-strontium titanate (Ba0.65Sr0.35TiO3) films doped with Ho3+(1mol%, 3mol%, 5mol%, 8mol%) were prepared by the sol-gel technique. The AFM, XRD, UV-Vis spectra and photoluminescence (PL) spectra of BST films were investigated. Results show that the lattice parameters of BST films increase when Ho3+ dopant increases from 1mol% to 3mol% then decrease with Ho3+ dopant from 3mol% to 8mol%. The lights centered at about 615, 650 and 750nm are corresponding to the transitions of 5F3→5F7, 5F5→5F8 and 5S2, 5F4→5F7, respectively. The lifetime spectra of 5S2, 5F4 and three PL spectra above indicate that the luminescence intensity reach the maximum in 3mol% Ho3+ -doped BST films. The optimized Ho3+ dopant in BST films is 3mol%. The crossing relaxation mechanisms and site-substituting between H 3+ and Ba2+/Sr2+/Ti4+ are analyzed.
[1] 刘梅冬, 许毓春. 压电铁电材料与器件. 武汉: 华中理工大学出版社, 1990. 44--154.
[2] 钟维烈, 铁电体物理学. 北京: 科学出版社, 1996.
[3] Hasegawa Y, Wada Y, Yanagida S. Photochemistry and Photobiology C: Photochemistry Reviews, 2004, 5 (3): 183--202.
[4] Pazik R, Hreniak D, Strek W, et al. Optical Materials, 2006, 28 (11): 1284--1288.
[5] Shen Cai, Liu Qian, Liu Qing-Feng. Materials Science and Engineering: B, 2004, 111 (1): 31--35.
[6] Samantaray C B, Nanda Goswami M L, Bhattacharya D, et al. Materials Letters, 2004, 58 (17-18): 2299--2301.
[7] Kim K T, Kim C. Thin Solid Films, 2005, 472 (1-2): 26--30.
[8] Chen M, Liu Z L, Wang Y. Physica B: Condensed Matter, 2004, 352 (1-4): 61--65.
[9] 张思远, 毕宪章. 稀土光谱理论. 吉林科学技术出版社, 1991. 31--66.
[10] Terasako T, Hashimoto K, Nomoto Y, et al. Journal of Luminescence, 2000, 87-89 (1): 1056--1058.
[11] Buddhudu S, Bryant F J, Xi L. Materials Letters, 1990, 9 (2-3): 109--112.
[12] Zaldo C, Martín M., Solé R, et al. Optical Materials, 1998, 10 (1): 29--37.
[13] Wuu D S, Horng R H, Lin C C. et al. Microelectronic Engineering, 2003, 66 (1-4): 600--607.
[14] Li J T, Dong X L. Materials Letters, 2005, 59 (23): 2863--2866.