Hierarchical Placement and Associated Optoelectronic Impact of Carbon Nanotubes in Polymer-Fullerene Solar Cells

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• 作者：Sumit Chaudhary ; Haiwei Lu ; Astrid M. Mü ; ller ; Christopher J. Bardeen ; Mihrimah Ozkan
• 刊名：Nano Letters
• 出版年：2007
• 出版时间：July 2007
• 年：2007
• 卷：7
• 期：7
• 页码：1973 - 1979
• 全文大小：687K
• 年卷期：v.7,no.7(July 2007)
• ISSN：1530-6992

文摘

Since their discovery, carbon nanotubes (CNTs) have been considered to be promising candidates for polymer-based solar cells, but theirfunctional incorporation and utilization in such devices have been limited due to processing bottlenecks. Here, we demonstrate the realizationof controlled placement of a single-walled CNT (SWNT) monolayer network at four different positions in polymer-fullerene bulk-heterojunction(BHJ) solar cells. SWNTs were deposited by dip-coating from a hydrophilic suspension, and a very brief, largely nondestructive argon plasmatreatment of the active layer was utilized for incorporation of a SWNT layer within or above it. We demonstrate that SWNTs on the hole-collection side of the active layer lead to an increase in power conversion efficiency (PCE) of the photovoltaic devices from 4 to 4.9% (underAM 1.5 G, 1.3 suns illumination). This is the highest reported PCE for polymer-based solar cells incorporating CNTs, upon consideration ofexpected scaling of device parameters for 1 sun illumination. We also observe that SWNTs deposited on the top of the active layer lead tomajor electro-optical changes in the device functionality, including an increased fluorescence lifetime of poly-3-hexylthiophene (P3HT).