Wang Bo, Lim Jia Wei Melvin, Loh Siow Mean, Mayengbam Rishikanta, Ye Senyun, Feng Minjun, He Huajun, Liang Xiao, Cai Rui, Zhang Qiannan, Kwek Leong-Chuan, Demir Hilmi Volkan, Mhaisalkar Subodh G, Blundell Steven A, Chien Sum Tze
Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
Université Grenoble Alpes, CEA, CNRS, IRIG, SyMMES, F-38000 Grenoble, France.
ACS Nano. 2024 Apr 23;18(16):10807-10817. doi: 10.1021/acsnano.3c12311. Epub 2024 Apr 10.
Colloidal perovskite quantum dots (PQDs) have emerged as highly promising single photon emitters for quantum information applications. Presently, most strategies have focused on leveraging quantum confinement to increase the nonradiative Auger recombination (AR) rate to enhance single-photon (SP) purity in all-inorganic CsPbBr QDs. However, this also increases the fluorescence intermittency. Achieving high SP purity and blinking mitigation simultaneously remains a significant challenge. Here, we transcend this limitation with room-temperature synthesized weakly confined hybrid organic-inorganic perovskite (HOIP) QDs. Superior single photon purity with a low (0) < 0.07 ± 0.03 and a nearly blinking-free behavior (ON-state fraction >95%) in 11 nm FAPbBr QDs are achieved at room temperature, attributed to their long exciton lifetimes () and short biexciton lifetimes (). The significance of the organic A-cation is further validated using the mixed-cation FACsPbBr. Theoretical calculations utilizing a combination of the Bethe-Salpeter (BSE) and approaches point toward the modulation of the dielectric constants by the organic cations. Importantly, our findings provide valuable insights into an additional lever for engineering facile-synthesized room-temperature PQD single photon sources.
胶体钙钛矿量子点（PQDs）已成为用于量子信息应用的极具前景的单光子发射器。目前，大多数策略都集中在利用量子限域来提高非辐射俄歇复合（AR）速率，以增强全无机CsPbBr量子点中的单光子（SP）纯度。然而，这也增加了荧光间歇性。同时实现高SP纯度和抑制闪烁仍然是一个重大挑战。在这里，我们通过室温合成的弱限域杂化有机-无机钙钛矿（HOIP）量子点克服了这一限制。在室温下，11 nm的FAPbBr量子点实现了优异的单光子纯度，其低（0）<0.07±0.03，并且具有几乎无闪烁的行为（开态分数>95%），这归因于它们长的激子寿命（）和短的双激子寿命（）。使用混合阳离子FACsPbBr进一步验证了有机A阳离子的重要性。结合贝塞耳-萨尔皮特（BSE）和方法的理论计算表明，有机阳离子可调节介电常数。重要的是，我们的研究结果为设计易于合成的室温PQD单光子源提供了另一个有价值的手段。
