Triplet sensitization via charge recombination at organic heterojunction for efficient near-infrared to visible solid-state photon upconversion
Triplet sensitization via charge recombination at organic heterojunction for efficient near-infrared to visible solid-state photon upconversion
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DOI：
10.1038/s43246-022-00300-z
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发表时间：
2022-10
影响因子：
7.8
通讯作者：
Yuji Sakamoto;S. Izawa;Hideo Ohkita;M. Hiramoto;Yasunari Tamai
中科院分区：
文献类型：
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作者：
Yuji Sakamoto;S. Izawa;Hideo Ohkita;M. Hiramoto;Yasunari Tamai
在固态下实现高效的近红外到可见光光子上转换是各个领域商业应用的关键。我们先前报道了一种模仿有机太阳能电池光伏转换机制的固态上转换器件。这导致了高达2.3%的外量子效率的显着提高，比传统器件高出两个数量级。在这里，我们调查该设备的上转换机制。我们研究激子和电荷的动态使用瞬态吸收光谱，发现约67%的入射光子被利用，由于快速单线态激子扩散的非富勒烯受体层。引人注目的是，三重态激子在施主/受主界面附近积累，使得三重态-三重态湮灭加速超过10倍。
Realizing efficient near-infrared to visible photon upconversion in the solid state is pivotal for commercial applications in various fields. We previously reported a solid-state upconversion device which imitated the photovoltaic conversion mechanisms of organic solar cells. This leads to a significant improvement of up to 2.3% in the external quantum efficiency, which is two orders of magnitude higher than that of conventional devices. Here, we investigate the upconversion mechanism of this device. We examine exciton and charge dynamics using transient absorption spectroscopy and find that approximately 67% of incident photons are utilized owing to fast singlet exciton diffusion in the nonfullerene acceptor layer. Strikingly, triplet excitons are accumulated near the donor/acceptor interface, enabling accelerated triplet–triplet annihilation by a factor of more than 10.