Mn4+掺杂的新型铝酸盐红色长余辉材料

用高温固相法合成了红色长余辉发光材料LiAl₅O₈:Mn⁴⁺,Li₅AlO₄:Mn⁴⁺,LiAlO₂:Mn⁴⁺,发现前两种材料有红色余辉,这方面并没有报道过,并对这两种材料的发光性能作了研究,指明了不同基质中发光强弱不同原因。对不同Mn⁴⁺掺杂浓度的材料做了浓度依赖关系研究,确认Mn⁴⁺的发光是²E→⁴A₂的跃迁。Mn⁴⁺的发光是个宽带谱,材料在紫外区有强的吸收,发射谱范围可达620~770nm,峰值在675nm。对长余辉机制进行了探讨。

New Red Long Afterglow Aluminate Materials Doped with Mn4+

As a new generation of long afterglow phosphors, rare earth doped aluminates are drawing more and more attention. However, though the blue and the green phosphors with excellent afterglow performance are put into commercial use, the red afterglow phosphor doped with Dy³⁺ or Tb³⁺ suitable for illuminating is still dissatisfied with the white afterglow phosphor. We developed a new way to meet the conditions of red afterglow phosphor: aluminates doped with Mn⁴⁺.Following this new method, we synthesize LiAl₅O₈:Mn⁴⁺,Li₅AlO₄:Mn⁴⁺, LiAlO₂:Mn⁴⁺,and find that the former two have red long afterglow, this have not been reported before, then the luminescent properties of the two kinds of materials were studied, the reason of different intensity in different hosts was pointed out. We also test the intensity-concentration curve, notate that the radiation of Mn⁴⁺ is due to transition of ²E→⁴A₂, its emission spectrum is a broad band, peaked at 675 nm. It absorb ultraviolet strongly, the excitation spectrum extends from 620 nm to 770 nm, At last we research the mechanism of long afterglow of these materials, discuss why the long afterglow properties are different between these kinds of materials.