Single‐Walled Carbon Nanotubes as an Additive in Organic Photovoltaics: Effects on Carrier Generation and Recombination Dynamics
Single‐Walled Carbon Nanotubes as an Additive in Organic Photovoltaics: Effects on Carrier Generation and Recombination Dynamics
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单壁碳纳米管作为有机光伏添加剂：对载流子生成和复合动力学的影响
DOI：
10.1002/solr.202101010
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发表时间：
2022
期刊：
影响因子：
7.9
通讯作者：
Larry Lüer
中科院分区：
文献类型：
--
作者：
Abasi Abudulimu;Klaus Eckstein;Mirella El Gemayel;Imge Namal;Adam B Phillips;Randy J Ellingson;Michael J Heben;Tobias Hertel;Sebastian B Meier;Larry Lüer
采用单壁碳纳米管（SWNTs）作为有机光催化剂（OPV）活性层的添加剂，以提高电荷提取在研究界越来越重要。虽然单壁碳纳米管可以比传统聚合物更快地传输载流子数量级，但它们也会淬灭激子和无陷阱电荷，从而降低器件性能。单壁碳纳米管对OPV器件性能的这种影响仍然没有得到充分研究和完全理解。在本文中，通过飞秒-微秒瞬态吸收光谱和瞬态光电压/光电流技术研究了富含（6，5）手性的单壁碳纳米管对两种不同OPV器件的电荷产生和提取特性的影响。结果表明，取决于供体材料的性质（例如，在能量学（energetic）中，SWNT可以通过淬灭激子来减少载流子的产生，并通过捕获过程来增加载流子的复合。然后，通过使用通过瞬态测量确定的参数对器件的电流-电压特性进行分析计算，结果表明，增加的重组也与单壁碳纳米管引起的形态变化有关。这些结果揭示了单壁碳纳米管的性能限制因素时，纳入太阳能电池的活性层。因此，这项工作可以加速高性能有机太阳能电池的共混物优化过程。
Employing single‐walled carbon nanotubes (SWNTs) as an additive in the active layer of organic photovoltaics (OPV) to improve charge extraction is gaining weight in the research community. While SWNTs can transport charge carriers orders of magnitudes faster than conventional polymers, they also quench excitons and trap‐free charges, reducing device performance. Such influences of SWNTs on OPV device performance remain inadequately explored and incompletely understood. Herein, the impact of SWNTs, enriched in (6,5) chirality, on the charge generation and extraction properties of two different OPV devices is studied by femtosecond‐microsecond transient absorption spectroscopy and transient photovoltage/photocurrent techniques. It is shown that depending on the donor material properties (e.g., energetics), SWNTs can reduce carrier generation by quenching the excitons and increase carrier recombination through trapping processes. Then, by performing an analytical calculation of the current–voltage characteristics of the devices using the parameters determined via the transient measurements, it is shown that the increased recombination also relates to morphological changes induced by the SWNTs. These results shed light on the performance limiting factors of the SWNTs when incorporated into the active layer of the solar cells. This work thus can accelerate the blend optimization process for high‐performance organic solar cells.