Highly Conductive PEDOT:PSS Treated with Formic Acid for ITO-Free Polymer Solar Cells
Highly Conductive PEDOT:PSS Treated with Formic Acid for ITO-Free Polymer Solar Cells
复制标题
DOI：
10.1021/am405024d
复制
发表时间：
2014-02-26
影响因子：
9.5
通讯作者：
Chu, Chih-Wei
中科院分区：
文献类型：
--
作者：
Mengistie, Desalegn A.;Ibrahem, Mohammed A.;Chu, Chih-Wei
我们提出了一种简单的薄膜处理与甲酸，以提高导电性的聚（3，4-乙撑二氧噻吩）：聚（苯乙烯磺酸）（PEDOT：PSS）的4个数量级。研究了甲酸浓度对电导率的影响;电导率随着浓度的增加而快速增加，直到10 M，然后略有增加，使用26 M浓度时的最高电导率为2050 S cm（-1）。甲酸处理的PEDOT：PSS膜也表现出非常高的透射率。通过SEM、AFM、XPS等分析手段探讨了导电增强的机理。甲酸的高介电常数屏蔽了PEDOT和PSS之间的电荷，导致它们之间的相分离。增加载流子浓度，从膜中去除PSS，形态和构象变化与延长和更好地连接PEDOT链的电导率增强的主要机制。ITO自由聚合物太阳能电池也制造使用PEDOT：PSS电极用不同浓度的甲酸处理，并表现出相同的性能的ITO电极。浓酸处理不损害所需的膜性质以及太阳能电池的稳定性和性能。
We proposed a facile film treatment with formic acid to enhance the conductivity of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) by 4 orders of magnitude. The effect of formic acid concentration on conductivity was investigated; conductivity increased fast with increasing concentration up to 10 M and then increased slightly, the highest conductivity being 2050 S cm(-1) using 26 M concentration. Formic acid treated PEDOT:PSS films also exhibited very high transmittances. The mechanism of conductivity enhancement was explored through SEM, AFM, and XPS. Formic acid with its high dielectric constant screens the charge between PEDOT and PSS bringing about phase separation between them. Increased carrier concentration, removal of PSS from the film, morphology, and conformation change with elongated and better connected PEDOT chains are the main mechanisms of conductivity enhancement. ITO-free polymer solar cells were also fabricated using PEDOT:PSS electrodes treated with different concentrations of formic acid and showed equal performance to that of ITO electrodes. The concentrated acid treatment did not impair the desirable film properties as well as stability and performance of the solar cells.