以具有一维结构的Sr2CeO4化合物为研究对象、Sm3+作为发光中心, 探索了其作为LED用荧光材料的可能性. 用高温固相法于1200℃、6h合成了Sr2CeO4:Sm3+系列单相粉末样品, 并研究了其发光性质. 结果表明, 在365nm激发下, 从荧光光谱中可以看出存在从基质向稀土离子的能量转移. 通过调节荧光材料Sr2CeO4:Sm3+中稀土离子Sm3+的掺杂浓度, 可以调谐发光体的发光颜色, 当Sm3+离子浓度较小(<3%)时, 体系发出很强的白光; 当Sm3+离子浓度较大(3%~15%)时, 体系发出红光. 测量了荧光材料的色坐标, 发现Sr2CeO4:1%Sm3+的色坐标是(0.334,0.320), 接近于纯白色(0.33,0.33), 可以作为一种新型的UV-LED用单一白色荧光材料.
The trivalent samarium doped Sr2CeO4 color-tunable phosphors were successfully synthesized by solid state reaction at 1200℃ for 6h and their luminescent characteristics were studied. The results indicate that the host can transfer its exciting energy to rare earth ion Sm3+ when excited with 365nm light. The emission color can be changed by tuning activator’s concentration in Sr2CeO4:Sm3+ phosphors. The doped compound emits strong white light when the concentration of the doped Sm3+ is lower than 3%. When the Sm3+ concentration is increased from 3% to 15%, it emits red light. The chromaticity coordinate of Sr2CeO4: 1% Sm3+ phosphor is measured
to be (x, y) (0.334, 0.320), which is closed to the pure white (0.33, 0.33). It shows that Sr2CeO4: 1% Sm3+ phosphor is a promising single white phosphor for ultraviolet light-emitting diode.
[1] Yukio N, Isamu N, Kunihiro I, et al. Jpn. J. Appl. Phys., 2002, 41 (4A): 371--373.
[2] Nakamura S. Solid State Commun., 1997, 102 (2-3): 237--248.
[3] Schlotter P, Baur J, Hielscher Ch, et al. Mater. Sci. Eng., 1999, 59 (1): 390--394.
[4] Toshio N, Tomoyuki B, Naoki K. Appl. Phys. Lett., 2003, 82 (22): 3817--3819.
[5] Danielson E, Devenney M, Giaquinta D M, et al. Science, 1998, 279 (6): 837--839.
[6] Danielson E, Devenney M, Giaquintu D M, et al. J. Mol. Struct., 1998, 470 (1-2): 229--235.
[7] Sankar R, Subba Rao G V. J. Electrochem. Soc., 2000, 147 (7): 2773--2779. [8] 高峰, 陈震. 稀有金属快报, 2005, 24 (12): 23--26.
[9] Takayuki Hirai, Yusuke Kawamura. J. Phys. Chem. B, 2004, 108 (34): 12763--12769.
[10] Jiang Y D, Zhang F, Christopher J, et al. Appl. Phys. Lett., 1999, 74 (12): 1677--1679.
[11] Serra O A, Severino V P, Galefi P S, et al. Journal of Alloys and Compounds, 2001, 323-324 (supp): 667--669.
[12] Tang Y X, Guo H P, Qin Q Z. Solid State Commun., 2002, 121 (6-7): 351--356.
[13] 翟永清, 周雪玲, 回学庄, 等. 化工新型材料, 2005, 33 (12): 33--35.
[14] 彭夷安, 林建华, 郭凤瑜. 光谱学与光谱分析, 1996, 16 (2): 9--14.
[15] 张国春, 傅佩珍, 王国富, 等. 发光学报, 2001, 22 (3): 237--242.
[16] Van Pieterson L, Soverna S, Meijerink A. J. Electrochem. Soc., 2000, 147 (12): 4688--4691.