Strong light-matter coupling for reduced photon energy losses in organic photovoltaics
Strong light-matter coupling for reduced photon energy losses in organic photovoltaics
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DOI：
10.1038/s41467-019-11717-5
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发表时间：
2019-08-16
影响因子：
16.6
通讯作者：
Vandewal, Koen
中科院分区：
文献类型：
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作者：
Nikolis, Vasileios C.;Mischok, Andreas;Vandewal, Koen
强的光-物质耦合作用可以使有机半导体中的激子能量发生重排。在这里，我们利用强耦合嵌入到一个光学微腔的无富勒烯的有机太阳能电池（OSC）的光活性层，导致形成的极化激元峰和红移的光学间隙。同时，器件的开路电压不受影响。这导致低能量极化激元的光子能量损失减少，吸收边变陡。虽然强耦合减小了光学带隙，但对于大驱动力的供体-受体系统，电荷转移态的能量不受影响。有趣的是，这意味着可以在OSC中利用强耦合来降低电子转移的驱动力，而无需对光敏层进行化学或微观结构修饰。我们的工作表明，决定OSC中电压损耗的过程现在可以调整，并降低到前所未有的值，只需操纵器件架构。
Strong light-matter coupling can re-arrange the exciton energies in organic semiconductors. Here, we exploit strong coupling by embedding a fullerene-free organic solar cell (OSC) photo-active layer into an optical microcavity, leading to the formation of polariton peaks and a red-shift of the optical gap. At the same time, the open-circuit voltage of the device remains unaffected. This leads to reduced photon energy losses for the low-energy polaritons and a steepening of the absorption edge. While strong coupling reduces the optical gap, the energy of the charge-transfer state is not affected for large driving force donor-acceptor systems. Interestingly, this implies that strong coupling can be exploited in OSCs to reduce the driving force for electron transfer, without chemical or microstructural modifications of the photoactive layer. Our work demonstrates that the processes determining voltage losses in OSCs can now be tuned, and reduced to unprecedented values, simply by manipulating the device architecture.