聚合物发光二极管中可逆的不稳定行为

研究了存在于聚合物发光二极管 ( PL ED)中的一种可逆的“负阻”现象及短期衰退行为 .当加在 PLED上的正向偏压大于 1 0 V之后 ,其电流和发光强度将在某偏压下出现突然的转折 ,即电流或光强骤增而器件上压降减小 .“负阻”现象将随测量次数的增加而逐渐消失 .采用 CCD摄像头摄取发光象素上发光的变化情况的图像 ,发现光强的突变与电流的突变是相对应的 .对以不同极性脉冲偏置观察发光光强的短期衰退情况时发现 ,反向偏置有助于抑制正向的发光衰退行为 .我们初步认为这些现象可能与 PLED中存在的缺陷态及其上电荷的填充状况有关

Recoverable Unstable Phenomena in PLED

A recoverable negative resistance phenomenon and short\|term degradation in polymer light emitting diode (PLED) have been investigated in this paper. When the bias on the PLED is higher than a certain voltage, an abrupt change will take place in the current and luminance of PLED. It means that the current and luminance of PLED will increase accompanied by the decrease of its voltage. At the same time, the negative phenomenon will disappear gradually along with the increase of measurement times. We use a charge\|coupled device (CCD) pick\|up camera to take images of the abrupt change of luminance and find that the change of luminance corresponds to that of current. The short\|term degradations of luminance under different polar bias are also studied and the negative bias mode is proved to restrain the degradation of luminance effectively. We suspect that the reason for above recoverable but unstable phenomena relates to the defects in PLED and the filling behavior of carriers in it.