Triplet Energy Transfer from Perovskite Nanocrystals Mediated by Electron Transfer
Triplet Energy Transfer from Perovskite Nanocrystals Mediated by Electron Transfer
复制标题
电子转移介导的钙钛矿纳米晶体的三重态能量转移
DOI：
10.1021/jacs.0c04583
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发表时间：
2020-06-24
影响因子：
15
通讯作者：
Wu, Kaifeng
中科院分区：
文献类型：
--
作者：
Luo, Xiao;Liang, Guijie;Wu, Kaifeng
从胶体纳米晶体的三重态能量转移是一种新的方法来敏化分子三重态，这对许多应用都很重要。最近的研究表明，这种三重态转移可以介导的空穴转移过程时，它是积极允许的。相比之下，尚未观察到电子转移介导的三重态转移，这可能是由于典型的II-VI族纳米晶体中的空穴捕获抑制了初始电子转移之后的空穴转移步骤，因此破坏了完整的三重态激子转移。在这里，我们报告了电子转移介导的三重态能量转移从CsPbCl 3和CsPbBr（3）钙钛矿纳米晶体的表面锚定的罗丹明分子。该机制是明确地建立了超快光谱;使用CdS纳米晶体的控制实验也证实了空穴捕获在抑制这种机制的作用。敏化的罗丹明三重态在光子上转换和单重态氧产生等方面有着广泛的应用。与传统的一步三重态转移相比，电子转移介导的机制在界面电子耦合方面要求较低，因此更普遍可实现。总体而言，本研究不仅建立了一个完整的框架，三重态能量转移跨晶体/分子界面，但也大大扩展了使用纳米晶体的分子三重态敏化的范围。
Triplet energy transfer from colloidal nanocrystals is a novel approach to sensitizing molecular triplets that are important for many applications. Recent studies suggest that this triplet transfer can be mediated by a hole transfer process when it is energetically allowed. In contrast, electrontransfer-mediated triplet transfer has not been observed yet, which is likely due to hole-trapping in typical II-VI group nanocrystals inhibiting the hole transfer step following initial electron transfer and hence disrupting a complete triplet exciton transfer. Here we report electron-transfer-mediated triplet energy transfer from CsPbCI3 and CsPbBr(3 )perovskite nanocrystals to surface-anchored rhodamine molecules. The mechanism was unambiguously established by ultrafast spectroscopy; control experiments using CdS nanocrystals also confirmed the role of hole-trapping in inhibiting this mechanism. The sensitized rhodamine triplets engaged in a variety of applications such as photon upconversion and singlet oxygen generation. Compared to conventional one-step triplet transfer, the electron-transfer-mediated mechanism is less demanding in terms of interfacial electronic coupling and hence is more generally implementable. Overall, this study not only establishes a complete framework of triplet energy transfer across nanocrystal/molecule interfaces but also greatly expands the scope of molecular triplet sensitization using nanocrystals.