Inorganic semiconductor nanocrystals interfaced with spin-triplet exciton-accepting organic molecules have emerged as promising materials for converting incoherent long-wavelength light into the visible range. However, these materials to date have made exclusive use of nanocrystals containing toxic elements, precluding their use in biological or environmentally sensitive applications. Here, we address this challenge by chemically functionalizing non-toxic silicon nanocrystals with triplet-accepting anthracene ligands. Photoexciting these structures drives spin-triplet exciton transfer from silicon to anthracene through a single 15 ns Dexter energy transfer step with a nearly 50% yield. When paired with 9,10-diphenylanthracene emitters, these particles readily upconvert 488-640 nm photons to 425 nm violet light with efficiencies as high as 7 ± 0.9% and can be readily incorporated into aqueous micelles for biological use. Our demonstration of spin-triplet exciton transfer from silicon to molecular triplet acceptors can critically enable new technologies for solar energy conversion, quantum information and near-infrared driven photocatalysis.

中文翻译：

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实现硅和分子受体之间的自旋三重态激子转移，以进行光子上转换。

与自旋三重态激子接受有机分子接口的无机半导体纳米晶体已经成为将无相干长波长光转换为可见光的有前途的材料。然而，迄今为止，这些材料已经排他性地使用了包含有毒元素的纳米晶体，从而排除了它们在生物或环境敏感应用中的使用。在这里，我们通过用三重态蒽配体化学功能化无毒的硅纳米晶体来应对这一挑战。光激发这些结构可驱动自旋三重态激子通过单个15 ns的Dexter能量转移步骤从硅转移至蒽，产率接近50％。与9,10-二苯基蒽发射体配对时，这些粒子可以将488-640 nm光子上转换为425 nm紫光，效率高达7±0。含量为9％，可以很容易地掺入水性胶束中用于生物用途。我们对自旋三重态激子从硅转移到分子三重态受体的演示可以为太阳能转化，量子信息和近红外驱动的光催化技术提供关键的新技术。