ITO/BTEO-PPV:PUI/Al的光电特性

Electrical and Electroluminescent Properties of ITO/BTEO-PPV∶PUI/Al

报道了用单离子导体聚氨酯酰亚胺磺酸钠(PUI)作为固体电解质和共聚[2,5 二(三乙氧基) 1,4 对苯乙炔] [1,4 对苯乙炔](BETO PPV)作为发光层的单离子聚合物发光电池(SLEC)的制作和测量。实验结果及其分析表明:不可移动阴离子的存在使SLEC的正反向稳态电流 电压(I V)曲线不再对称;SLEC具有快速响应的主要原因是SLEC中固定的阴离子对阳离子的散射比LEC中运动的阴离子对阳离子散射小。SLEC的电容 频率(C f)特性证实了阳离子在薄膜中具有较快的响应速度。

Because ionized polyurethane-poly(ethylene glycol) copolymer(PUI) and poly[1,4- (2,5-bis(1,4,7-ethoxy) phenylene vinylene)-alt-1,4-(phenylene vinylene)](BETO-PPV) can be mixed well,we use PUI as polymer electrolyte and BETO-PPV as luminescent polymer to fabricate light-emitting electrochemical cell (SLEC). The device structure is identical to traditional LEC. The fabrication of SLEC and measurement of the electrical and electroluminescent characteristics were reported,and the experimental results were discussed by an electrodynamic model. Experiments and analyses show, because of congregate of cations,SLEC has a low turn-on voltage and Al can be employed as cathode as traditional LEC. Due to low density of immobile anions in PUI, steady-state current-voltage character depends on the height of the barrier for hole injection. So the curve of SLEC's steady-state current-voltage character is imsymmetrical. In addition,the most important characteristic of SLEC is the fast light-emitting response. The response time of SLEC is about 10 ms, faster two orders of magnitude under a fixed bias than that of traditional LEC. By analyses of chemical character of BETO-PPV and PUI, it shows that oligo(ethylene oxide) side groups of BETO-PPV chains are stick to PUI chains so that the compound film of PUI and BETO-PPV forms a continuous network phase enabling fast ion transport. Another reason enabling fast ion transport is that a local ordered potential formed by fixed anions of SLEC forms less scatter for mobile cations than the disordered potential formed by mobile anions of traditional LEC. C-f characteristics conform SLEC's fast time response.