Improving the photoluminescence quantum yields of quantum dot films through a donor/acceptor system for near-IR LEDs
Improving the photoluminescence quantum yields of quantum dot films through a donor/acceptor system for near-IR LEDs
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DOI：
10.1039/c8mh01122b
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发表时间：
2019-01-01
影响因子：
13.3
通讯作者：
Greenham, Neil C.
中科院分区：
文献类型：
--
作者：
Davis, Nathaniel. J. L. K.;Allardice, Jesse R.;Greenham, Neil C.
近红外发光二极管（LED）显示出在电信和医疗应用方面的潜力。量子点纳米晶体（QD），特别是铅硫族化物，是候选LED材料，因为它们在整个近红外区域表现出可调谐的发光，但它们的表面结构必须仔细控制以实现有效的发射。我们展示了一个有效的施主-受主量子点系统，通过嵌入具有高光致发光量子效率（PLQE）的低能量子点到具有较低PLQE的高能量子点矩阵。我们发现，整体PLQE的密集包装的交联量子点膜可以通过纳入一个相对较小的部分，以及钝化的受体量子点，也导致改善LED的性能得到改善。激发被转移到隔离的低能受体量子点，在那里它们以高辐射效率重组。
Near-infrared light-emitting diodes (LEDs) show potential for telecommunication and medical applications. Quantum dot nanocrystals (QDs), specifically lead chalcogenides, are candidate LED materials since they exhibit tuneable luminescence across the whole near-infrared region, but their surface structure must be carefully controlled to achieve efficient emission. We demonstrate an efficient donor-acceptor QD system by embedding low-energy QDs with high photoluminescence quantum efficiency (PLQE) into a matrix of higher-energy QDs with lower PLQE. We find that the overall PLQE of densely packed cross-linked QD films can be improved by the incorporation of a relatively small fraction of well-passivated acceptor QDs, also leading to improved LED performance. Excitations are transferred into the isolated low-energy acceptor QDs, where they recombine with high radiative efficiency.