Effect of fractal silver electrodes on charge collection and light distribution in semiconducting organic polymer films
Effect of fractal silver electrodes on charge collection and light distribution in semiconducting organic polymer films
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DOI：
10.1039/c4ta03204g
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发表时间：
2014-09
影响因子：
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通讯作者：
Rachel L. Chamousis;Lilian Chang;W. Watterson;R. Montgomery;Richard P. Taylor;A. Moulé;S. Shaheen;B. Ilan;J. Lagemaat;F. Osterloh
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作者：
Rachel L. Chamousis;Lilian Chang;W. Watterson;R. Montgomery;Richard P. Taylor;A. Moulé;S. Shaheen;B. Ilan;J. Lagemaat;F. Osterloh
生物体使用分形结构来优化不同大小尺度区域之间的物质和能量传输。在这里，我们测试的分形银电极的光分布和电荷收集的有机半导体聚合物薄膜制成的P3 HT和PCBM的效果。将半导体聚合物沉积到电化学生长的分形银结构（5000 nm × 500 nm;分形维数为1.71）上，PEDOT：PSS作为空穴选择性中间层。分形银电极由于增加的水平光散射而呈现黑色，这被示出改善聚合物中的光吸收。根据表面光电压谱，分形银电极优于平面电极时，BHJ膜厚度大（>400 nm，0.4 V的光电压）。在435 nm LED（10-20 mW cm−2）照射下，在含有0.005 M六氟磷酸二茂铁盐作为电子受体的乙腈溶液中，从体异质结（BHJ）光电极产生高达200微安cm−2的光电流。低IPCE值（0.3-0.7%）是由于缓慢的电子转移到二茂铁离子和由于沿大的金属-聚合物界面沿着分流。总体而言，这项工作提供了一个初步评估的有机光伏电池的分形电极的潜力。
Living organisms use fractal structures to optimize material and energy transport across regions of differing size scales. Here we test the effect of fractal silver electrodes on light distribution and charge collection in organic semiconducting polymer films made of P3HT and PCBM. The semiconducting polymers were deposited onto electrochemically grown fractal silver structures (5000 nm × 500 nm; fractal dimension of 1.71) with PEDOT:PSS as hole-selective interlayer. The fractal silver electrodes appear black due to increased horizontal light scattering, which is shown to improve light absorption in the polymer. According to surface photovoltage spectroscopy, fractal silver electrodes outperform the flat electrodes when the BHJ film thickness is large (>400 nm, 0.4 V photovoltage). Photocurrents of up to 200 microamperes cm−2 are generated from the bulk heterojunction (BHJ) photoelectrodes under 435 nm LED (10–20 mW cm−2) illumination in acetonitrile solution containing 0.005 M ferrocenium hexafluorophosphate as the electron acceptor. The low IPCE values (0.3–0.7%) are due to slow electron transfer to ferrocenium ion and due to shunting along the large metal–polymer interface. Overall, this work provides an initial assessment of the potential of fractal electrodes for organic photovoltaic cells.