复合结构粉末直流电致发光(CS—DCEL)屏的双光脉冲现象的初步研究

本文首次报导了粉末ZnS:Mn.Cu复合结构直流电致发光(CS—DCEL)屏在电脉冲激发下出现现的双光脉冲现象。这种结构的屏与普通DCEL屏的不同之处在于,其发光层和ITO导电膜层之间镀有一厚约0.4μm绝缘性良好的绝缘介质层。当用电脉冲激发时,黄色光(～5850Å)脉冲不仅出现于电脉冲前沿,还出现于其后沿附近;且正向电脉冲激发时,前沿光脉冲强度大于后沿,反向电脉冲激发时前沿小于后沿。 在电脉冲后沿附近出现第二个光脉冲的现象以及在实验中观察到的其它现象都可利用一个我们建立的模型——发光层与绝缘层界面附近自由电荷层的积累——予以较满意的解释。 另外,CS—DCEL屏在交变电压驱动下具有较好的老化特性和较高的发光效率,它可能成为将来很有前景的一种发光显示器件。

DOUBLE LIGHT PULSES PHENOMENON IN POWDER ZnS:Mn Cu COMPLEX STRUCTURE DCEL PANELS

In this paper, double light pulses phenomenon in powder ZnS :Mn, Cu complex structure DCEL (CS-DCEL) panels is firstly reported. A layer of higher insulator film (Y2O3 film, 0.4 m thickness) was deposited between ITO conductive film and ZnS: Mn,Cu powder layer in this kind of complex structure panels. The response of the yellow powder ZnS:Mn,Cu CS-DCEL panels to a pulsed voltage is marked by a luminescence peak not only at the leading edge but also at the trailing edge of the pulse. The height of the leading peak is larger than that of the trailng peak when the panels excited positively, but it is less than that of the trailing peak when excited reversely, and both of the peaks grows as the exciting pulse voltage (Vp) increased.All the observed results are interpreted satisfactorily by a model that attributes the trailing peak to the free electric charges accummulated at the phosphor-insulator interface during the pulse voltage exciting.When CS-DCEL panels are driven under alternating and pulsing current, it is showing a better aging characteristics and a higher luminescent efficiency, and it might be a good luminescent panels in the future.