Combinatorial Chemistry on Solid Supports. Topics in Current Chemistry, 278 Edited by Stefan Bräse (Universität Karlsruhe, Germany). Springer: Berlin, Heidelberg, New York. 2007. xii + 360.
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- 作者：Rolando Perez-Pineiro ; Hicham Fenniri ; H. Fenniri
- 刊名：Journal of the American Chemical Society
- 出版年：2008
- 出版时间：April 2, 2008
- 年：2008
- 卷：130
- 期：13
- 页码：4569 - 4570
- 全文大小：28K
- 年卷期：v.130,no.13(April 2, 2008)
- ISSN：1520-5126
文摘
We demonstrate that electrochemical side-reactions involving the electrolyte can be a significantand undesired feature in light-emitting electrochemical cells (LECs). By direct optical probing of planarLECs, comprising Au electrodes and an active material mixture of {poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) + poly(ethylene oxide) (PEO) + KCF3SO3}, we show that two directconsequences of such a side-reaction are the appearance of a "degradation layer" at the negative cathodeand the formation of the light-emitting p-n junction in close proximity to the cathode. We further demonstratethat a high initial drive voltage and a high ionic conductivity of the active material strongly alleviate theextent of the side reaction, as evidenced by the formation of a relatively centered p-n junction, and alsorationalize our findings in the framework of a general electrochemical model. Finally, we show that thedoping concentrations in the doped regions at the time of the p-n junction formation are independent ofthe applied voltage and relatively balanced at ~0.11 dopants/MEH-PPV repeat unit in the p-type regionand ~0.15 dopants/MEH-PPV repeat unit in the n-type region.