Evidence for Field-Dependent Charge Separation Caused by Mixed Phases in Polymer–Fullerene Organic Solar Cells
Evidence for Field-Dependent Charge Separation Caused by Mixed Phases in Polymer–Fullerene Organic Solar Cells
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聚合物富勒烯有机太阳能电池中混合相引起场相关电荷分离的证据
DOI：
10.1021/acs.jpclett.0c03863
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Collins, Brian A.
中科院分区：
文献类型：
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作者：
Dhakal, Prabodh;Ferron, Thomas;Alotaibi, Awwad;Murcia, Victor;Alqahtani, Obaid;Collins, Brian A.
随着有机光伏性能接近20%的效率，因果结构-性能关系必须建立设备实现理论极限，并成为商业竞争力。在这里，我们揭示了在聚合物-富勒烯太阳能电池中混合供体-受体界面和电荷产生之间的因果关系的证据。为此，我们结合联合收割机与定量同步加速器X射线纳米表征的器件性能的整体损耗分析，以确定场依赖性孪晶复合和纳米畴纯度之间>98%的相关性。重要的是，我们的分析排除了对业绩趋势的其他可能解释，这是建立因果关系的要求。我们分析的前所未有的粒度水平也分离了界面处的场依赖性和场独立性复合，在那里我们第一次发现该系统没有场独立性复合，这是一种困扰高性能系统的损耗通道，包括那些具有非富勒烯受体的系统。这一结果拓宽了最小化混合相以促进纯聚集域之间的尖锐界面是实现有机光致发光理论效率极限的理想纳米结构的情况。
As organic photovoltaic performance approaches 20% efficiencies, causal structure–performance relationships must be established for devices to realize theoretical limits and become commercially competitive. Here, we reveal evidence of a causal relationship between mixed donor–acceptor interfaces and charge generation in polymer–fullerene solar cells. To do this, we combine a holistic loss analysis of device performance with quantitative synchrotron X-ray nanocharacterization to identify a >98% anticorrelation between field-dependent geminate recombination and nanodomain purity. Importantly, our analysis eliminates other possible explanations of the performance trends, a requirement to establish causality. The unprecedented granular level of our analysis also separates field-dependent and field-independent recombination at the interface, where we find for the first time that this system is free of field-independent recombination, a loss channel that plagues high-performance systems, including those with non-fullerene acceptors. This result broadens the case that minimizing mixed phases to promote sharp interfaces between pure aggregated domains is the ideal nanostructure for realizing theoretical efficiency limits of organic photovoltaics.