Green-to-Blue Triplet Fusion Upconversion Sensitized by Anisotropic CdSe Nanoplatelets
Green-to-Blue Triplet Fusion Upconversion Sensitized by Anisotropic CdSe Nanoplatelets
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DOI：
10.26434/chemrxiv.9789482.v1
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发表时间：
2019-09
影响因子：
8.6
通讯作者：
Zachary A. VanOrman;Alexander S. Bieber;S. Wieghold;L. Nienhaus
中科院分区：
文献类型：
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作者：
Zachary A. VanOrman;Alexander S. Bieber;S. Wieghold;L. Nienhaus
绿蓝光子上转换在光催化应用中具有巨大潜力。然而，目前利用球形 CdSe 纳米晶体的混合无机-有机上转换方案通常受到能量多分散性、低量子产率以及由于表面钝化无机壳的必要性而产生的额外隧道势垒的限制。在这篇文章中，我们引入了各向异性 CdSe 纳米片作为三重态敏化剂。在这里，量子限制仅发生在一个方向，消除了由能量多分散性引起的效应。我们研究了从 CdSe 纳米片到表面结合的三重态受体 9-蒽羧酸的三重态能量转移。我们进一步关注纳米片堆叠和单线态反向传输对观察到的上转换效率的影响。我们使用湮灭器9,10-二苯基蒽在11 W/cm2的功率密度下获得了5.4%的上转换量子产率，以及237 mW/cm2的低效率阈值Ith。
Green-to-blue photon upconversion bears great potential in photocatalytic applications. However, current hybrid inorganic-organic upconversion schemes utilizing spherical CdSe nanocrystals are often limited by energetic polydispersity, low quantum yields and an additional tunneling barrier resulting from the necessity of surface-passivating inorganic shells. In this contribution, we introduce anisotropic CdSe nanoplatelets as triplet sensitizers. Here, quantum confinement occurs in only one direction, erasing effects stemming from energetic polydispersity. We investigate the triplet energy transfer from the CdSe nanoplatelets to the surface-bound triplet acceptor 9-anthracene carboxylic acid. We further focus on the influence of nanoplatelet stacking and singlet back transfer on the observed upconversion efficiency. We obtain an upconversion quantum yield of 5.4% at a power density of 11 W/cm2 using the annihilator 9,10-diphenylanthracene, and a low efficiency threshold Ith of 237 mW/cm2.