反向偏压下的压控颜色可调谐聚合物电致发光

Color Tunable Polymer Light-emitting Diodes Based on Heterojunction under Negative Bias

成功制备了结构为 ITO/ PDDOPV/ PPQ/ Al的异质结聚合物发光二极管 ,其中 PDDOPV是 p型聚合物材料 ,PPQ是 n型聚合物材料。该器件在正、反向偏压下均可发光。在正向偏压下的光发射主要来自 PDDOPV;在反向偏压下的光发射来自 PPQ的蓝光发射和 PDDOPV的黄光发射。蓝光强度与黄光强度的比值随着反向偏压的增加而增加。换句话说 ,该器件的发光颜色是压控可调的。这对实现彩色显示是极为有利的。

Light-emitting diodes based on heterojunction with structure ITO/PDDOPV/PPQ/Al have been successfully fabricated,in which PDDOPV is a p-type polymer while PPQ is an n-type polymer.Light emission was observed under both positive and negative bias voltage.Light emissionm under positive bias voltage mainly is originated from PDDOPV,but light emission under negative bias voltage includes blue light emission which is from PPQ and yellow emission which is from PDDOPV.The ratio of intensity of blue emission to that of yellow emission increases with the growth of negative bias voltage.In another word,the emitting color is voltage-dependent color tunable,which is a promising property to realize colorful display.The light emitting mechanism under negative bias voltage is analyzed.