Hill Sean P, Banerjee Tanmay, Dilbeck Tristan, Hanson Kenneth
Department of Chemistry and Biochemistry, Florida State University , Tallahassee, Florida 32306, United States.
J Phys Chem Lett. 2015 Nov 19;6(22):4510-7. doi: 10.1021/acs.jpclett.5b02120. Epub 2015 Nov 4.
Molecular photon upconversion via triplet-triplet annihilation (TTA-UC), combining two or more low energy photons to generate a higher energy excited state, is an intriguing strategy to surpass the maximum efficiency for a single junction solar cell (<34%). Here, we introduce self-assembled bilayers on metal oxide surfaces as a strategy to facilitate TTA-UC emission and demonstrate direct charge separation of the upconverted state. A 3-fold enhancement in transient photocurrent is achieved at light intensities as low as two equivalent suns. This strategy is simple, modular and offers unprecedented geometric and spatial control of the donor-acceptor interactions at an interface. These results are a key stepping stone toward the realization of an efficient TTA-UC solar cell that can circumvent the Shockley-Queisser limit.
通过三重态-三重态湮灭实现的分子光子上转换（TTA-UC），即结合两个或更多低能量光子以产生更高能量的激发态，是一种超越单结太阳能电池最大效率（<34%）的有趣策略。在此，我们介绍在金属氧化物表面自组装双层膜作为促进TTA-UC发射并证明上转换态直接电荷分离的一种策略。在低至两个等效太阳光照强度下，瞬态光电流实现了3倍增强。该策略简单、模块化，并在界面处对供体-受体相互作用提供了前所未有的几何和空间控制。这些结果是迈向实现可规避肖克利-奎塞尔极限的高效TTA-UC太阳能电池的关键一步。
