Krivenkov Victor, Goncharov Simon, Samokhvalov Pavel, Sánchez-Iglesias Ana, Grzelczak Marek, Nabiev Igor, Rakovich Yury
National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) , 115409 Moscow , Russian Federation.
CIC biomaGUNE , Paseo de Miramón 182 , 20014 Donostia-San Sebastián , Spain.
J Phys Chem Lett. 2019 Feb 7;10(3):481-486. doi: 10.1021/acs.jpclett.8b03549. Epub 2019 Jan 17.
Semiconductor quantum dots (QDs) are known for their ability to exhibit multiphoton emission caused by recombination of biexcitons (BX). However, the quantum yield (QY) of BX emission is low due to the fast Auger process. Plasmonic nanoparticles (PNPs) provide an attractive opportunity to accelerate BX radiative recombination. Here, we demonstrate the PNPs induced distance-controlled enhancement of BX emission of single QDs. Studying the same single QD before and after its integration with the PNPs, we observed a plasmon-mediated increase in the QY of BX emission. Remarkably, the enhancement of BX emission remains pronounced even at distances of 170 nm. We attribute this effect to efficient coupling, which results in the trade-off between resonance energy transfer from QD to gold nanorods and the Purcell effect at small QD-PNP separations and the predominant influence of the Purcell effect at longer distances. Our findings constitute a reliable approach to managing the efficiency of multiexciton emission over a wide span of distances, thus paving the way for new applications.
半导体量子点（QDs）以其能够展现由双激子（BX）复合引起的多光子发射而闻名。然而，由于快速的俄歇过程，BX发射的量子产率（QY）较低。等离子体纳米颗粒（PNPs）为加速BX辐射复合提供了一个有吸引力的机会。在这里，我们展示了PNPs诱导的单个量子点BX发射的距离控制增强。在将单个量子点与PNPs整合前后对其进行研究，我们观察到等离子体介导的BX发射QY增加。值得注意的是，即使在170 nm的距离处，BX发射的增强仍然很显著。我们将这种效应归因于有效耦合，这导致了在小量子点 - PNP间距下从量子点到金纳米棒的共振能量转移与珀塞尔效应之间的权衡，以及在较长距离下珀塞尔效应的主导影响。我们的发现构成了一种在宽距离范围内管理多激子发射效率的可靠方法，从而为新应用铺平了道路。
