Efficient Charge Generation via Hole Transfer in Dilute Organic Donor–Fullerene Blends
Efficient Charge Generation via Hole Transfer in Dilute Organic Donor–Fullerene Blends
复制标题
通过稀有机供体富勒烯混合物中的空穴转移有效产生电荷
DOI：
10.1021/acs.jpclett.0c00058
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Ogilvie, Jennifer P.
中科院分区：
文献类型：
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作者：
Song, Yin;Schubert, Alexander;Liu, Xiao;Bhandari, Srijana;Forrest, Stephen R.;Dunietz, Barry D.;Geva, Eitan;Ogilvie, Jennifer P.
高效的有机光致发光材料（OPV）需要具有接近单位量子产率的宽带电荷光生。这只能通过利用产生电荷的所有途径来实现。从有机供体到受体的电子转移已经被充分研究，并且被认为是OPV中电荷光生的主要途径。相比之下，对空穴传输路径的了解要少得多。在这里，我们使用我们最近开发的多光谱二维电子光谱学（M-2DES）研究了由四苯基二苯并二氢萘：C70混合物组成的原型系统中的电荷光生，并得到了时间相关密度泛函理论和完全量子力学费米黄金法则速率计算的支持。我们的方法确定在真实的时间两个快速的电荷转移途径，通过计算分析确认。令人惊讶的是，我们发现，电子和空穴转移发生具有可比的速率和效率，促进供体-受体电子相互作用。我们的研究结果突出了空穴传输路径的重要性，优化效率的OPV器件采用小分子异质结。
Efficient organic photovoltaics (OPVs) require broadband charge photogeneration with near-unity quantum yield. This can only be achieved by exploiting all pathways that generate charge. Electron transfer from organic donors to acceptors has been well-studied and is considered the primary path to charge photogeneration in OPVs. In contrast, much less is known about the hole transfer pathway. Here we study charge photogeneration in an archetypal system comprising tetraphenyldibenzoperiflanthene:C70blends using our recently developed multispectral two-dimensional electronic spectroscopy (M-2DES), supported by time-dependent density functional theory and fully quantum-mechanical Fermi’s golden rule rate calculations. Our approach identifies in real time two rapid charge transfer pathways that are confirmed through computational analysis. Surprisingly, we find that both electron and hole transfer occur with comparable rates and efficiencies, facilitated by donor–acceptor electronic interactions. Our results highlight the importance of the hole transfer pathway for optimizing the efficiency of OPV devices employing small-molecule heterojunctions.