Efficiency limitations in a low band-gap diketopyrrolopyrrole-based polymer solar cell.
Efficiency limitations in a low band-gap diketopyrrolopyrrole-based polymer solar cell.
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DOI：
10.1039/c4cp00485j
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发表时间：
2014-03
期刊：
影响因子：
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通讯作者：
S. Albert-Seifried;Doo‐Hyun Ko;S. Hüttner;C. Kanimozhi;S. Patil;R. Friend
中科院分区：
文献类型：
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作者：
S. Albert-Seifried;Doo‐Hyun Ko;S. Hüttner;C. Kanimozhi;S. Patil;R. Friend
报道了一种用于体相异质结器件的低带隙二酮基吡咯共聚物与PC71BM的性能和光物理性能。结果表明，聚合物中光生激子的短寿命限制了激子在施主-受主异质结中的扩散范围，从而阻碍了器件的效率。我们使用超快瞬变探针和荧光光谱技术来检测器件内部的激发态损耗通道。我们使用高沸点溶剂添加剂1，8-二碘正辛烷(DIO)研究了不同形态共混物的光激发态损失。该溶剂添加剂在施主和受主材料之间起到相容剂的作用，并导致更小的磁区尺寸、更高的电荷形成产率和更高的器件效率。
We report the performance and photophysics of a low band-gap diketopyrrolopyrrole-based copolymer used in bulk heterojunction devices in combination with PC71BM. We show that the short lifetime of photogenerated excitons in the polymer constitutes an obstacle towards device efficiency by limiting the diffusion range of the exciton to the donor-acceptor heterojunction. We employ ultrafast transient-probe and fluorescence spectroscopy techniques to examine the excited state loss channels inside the devices. We use the high boiling point solvent additive 1,8-diiodooctane (DIO) to study the photoexcited state losses in different blend morphologies. The solvent additive acts as a compatibiliser between the donor and the acceptor material and leads to smaller domain sizes, higher charge formation yields and increased device efficiency.