Chaudhary Sumit, Lu Haiwei, Müller Astrid M, Bardeen Christopher J, Ozkan Mihrimah
Department of Electrical Engineering and Chemistry Department, University of California, Riverside, California 92521, USA.
Nano Lett. 2007 Jul;7(7):1973-9. doi: 10.1021/nl070717l. Epub 2007 Jun 15.
Since their discovery, carbon nanotubes (CNTs) have been considered to be promising candidates for polymer-based solar cells, but their functional incorporation and utilization in such devices have been limited due to processing bottlenecks. Here, we demonstrate the realization of 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 plasma treatment 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% (under AM 1.5 G, 1.3 suns illumination). This is the highest reported PCE for polymer-based solar cells incorporating CNTs, upon consideration of expected scaling of device parameters for 1 sun illumination. We also observe that SWNTs deposited on the top of the active layer lead to major electro-optical changes in the device functionality, including an increased fluorescence lifetime of poly-3-hexylthiophene (P3HT).
自从被发现以来，碳纳米管（CNTs）就被认为是基于聚合物的太阳能电池的有前途的候选材料，但由于加工瓶颈，它们在这类器件中的功能整合和利用受到了限制。在这里，我们展示了在聚合物-富勒烯本体异质结（BHJ）太阳能电池的四个不同位置实现单壁碳纳米管（SWNT）单层网络的可控放置。通过从亲水性悬浮液中浸涂来沉积SWNTs，并对活性层进行非常短暂、基本无损的氩等离子体处理，以在其内部或上方掺入SWNT层。我们证明，活性层空穴收集侧的SWNTs可使光伏器件的功率转换效率（PCE）从4%提高到4.9%（在AM 1.5 G、1.3倍太阳光照下）。考虑到1倍太阳光照下器件参数的预期缩放，这是报道的掺入CNTs的基于聚合物的太阳能电池的最高PCE。我们还观察到，沉积在活性层顶部的SWNTs会导致器件功能发生重大电光变化，包括聚3-己基噻吩（P3HT）的荧光寿命增加。
