Achieving spin-triplet exciton transfer between silicon and molecular acceptors for photon upconversion
Achieving spin-triplet exciton transfer between silicon and molecular acceptors for photon upconversion
复制标题
DOI：
10.1038/s41557-019-0385-8
复制
发表时间：
2020-02-01
期刊：
影响因子：
21.8
通讯作者：
Roberts, Sean T.
中科院分区：
文献类型：
--
作者：
Xia, Pan;Raulerson, Emily K.;Roberts, Sean T.
无机半导体纳米晶体与自旋三重态激子接受有机分子的界面已经成为将非相干长波长光转换到可见光范围的有前途的材料。然而，迄今为止，这些材料仅使用含有有毒元素的纳米晶体，排除了它们在生物或环境敏感应用中的用途。在这里，我们通过化学官能化无毒硅纳米晶体与三重态接受蒽配体来解决这一挑战。光激发这些结构驱动自旋三重态激子转移从硅到蒽通过一个单一的15 ns德克斯特能量转移步骤，近50%的产率。当与9，10-二苯基蒽发光体配对时，这些颗粒容易将488-640 nm的光子上转换为425 nm的紫光，效率高达7 +/- 0.9%，并且可以容易地掺入水胶束中用于生物用途。我们证明了从硅到分子三重态受体的自旋三重态激子转移可以关键地实现太阳能转换，量子信息和近红外驱动的量子点的新技术。用能量接受染料功能化的量子点有望将低能光子转换为更高能量的可见光，用于生物成像，催化和太阳能收集。现在，已经表明无毒的硅量子点可以用于这些系统;已经观察到自旋三重态激子转移到其表面的分子。
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.Quantum dots functionalized with energy-accepting dyes hold promise for converting low-energy photons into higher-energy visible light for bioimaging, catalysis and solar energy harvesting. Now, it has been shown that non-toxic silicon quantum dots can be used in these systems; the transfer of spin-triplet excitons to molecules at their surface has been observed.