铥、铽及铕离子掺杂的BaAl2O4膜的阴极射线发光特性

利用喷雾热解法合成了Tm、Tb及Eu离子掺杂的铝酸钡(BaAl₂O₄)发光膜,研究了合成条件对其结构和发光特性的影响.在退火温度达到700℃时,生成了BaAl₂O₄膜.Tm³⁺和Tb³⁺掺杂的BaAl₂O₄膜分别发蓝光和绿光,而Eu³⁺掺杂的BaAl₂O₄膜的发光既有Eu²⁺的特征发射——宽的蓝光发射带,也有Eu³⁺的特征发射——窄的红光发射峰.BaAl₂O₄:Tm³⁺的发射主峰位于462nm,在电压为5kV和电流密度为57μA/cm²的条件下,其阴极射线发光(CL)亮度可达25cd/m²,效率可达0.11lm/W.BaAl₂O₄:Tb³⁺的发射主峰位于549nm,在相同的条件下,其阴极射线发光亮度可达120cd/m²,效率可达0.55lm/W.BaAl₂O₄:Eu³⁺的发射主峰位于616nm,其阴极射线发光亮度为50cd/m²,效率为0.23lm/W.BaAl₂O₄:Eu²⁺发蓝光,峰值位于452nm,其阴极射线发光亮度为640cd/m²,效率为2.93lm/W.

Cathodoluminescence of BaAl2O4 Films Co-doped with Tm,Tb and Eu

The most efficient phosphors currently available for fluorescent lamps, cathode-ray tubes, and flat panel displays are sulfides. Recently, there is growing interest in developing thin film oxide phosphors doped with transition metal or rare earth ions because they are chemically and thermally more stable. In addition, it is well known that thin film phosphors have advantages such as high contrast ratio, high ambient visibility, high image resolution and good heat resistance in display applications. For these reasons oxide-based thin film phosphors have been widely studied.In this paper, thin films of barium aluminate (BaAl₂O₄) doped separately with thulium, terbium, and europium were deposited by a spray pyrolysis method. The effects of preparation conditions on the structural and luminescence properties of the films were investigated. Polycrystalline BaAl₂O₄ films were formed at an annealing temperature above 700℃. Tm³⁺ and Tb³⁺ doped films deposited on glass emitted blue and green light, respectively. While in the films doped with europium, both red emission lines from Eu³⁺ and a broad blue or blue-green emission band from Eu²⁺ were observed. The BaAl₂O₄: Tm³⁺ film has the main emission wavelength at 462nm, and the highest cathodoluminescence (CL) luminance and efficiency at 5kV and 57μA/cm² were 25cd/m² and 0.11lm/W, respectively. For the BaAl₂O₄: Tb³⁺ film with the main wavelength at 549nm, the highest CL luminance and efficiency at the same condition were 120cd/cm² and 0.55 lm/W, respectively. A luminance of 50cd/m² and efficiency of 0.23lm/W were obtained for red emission at 616nm of the BaAl₂O₄: Eu³⁺ film grown on glass. Bright blue emission peaking at 452nm was obtained in the BaAl₂O₄: Eu²⁺ film grown on an aluminosilicate ceramic plate and annealed in N₂:H₂ (95:5) at 1100℃. Its luminance and efficiency were 640cd/m² and 2.93lm/W, respectively.