Pathak Sushil Swaroop, Kedarnath Gotluru, Panchakarla Leela S
Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
J Phys Chem Lett. 2023 Sep 14;14(36):8114-8120. doi: 10.1021/acs.jpclett.3c02180. Epub 2023 Sep 5.
Self-assembling of nanoparticles into complex superstructures is very challenging, which usually depends on postorganizing techniques or pre-existing templates such as polypeptide chains or DNA or external stimulus. Such self-assembled processes typically lead to close-packed structures. Here, it has been demonstrated that under carefully template-free reaction conditions CdS quantum dots (QDs) could be synthesized and simultaneously self-assembled into complex superstructures without compromising individual QD properties. The superstructures of CdS QDs attained by the chemical-based method demonstrate Stokes-shifted photoluminescence (PL) from trap states. Remarkably, the PL decay of superstructures exhibits a single-exponential feature. This behavior is unusual for the synthesized superstructures, indicating that the trap states are restricted to a narrow range. The growth mechanism of these superstructures is explained through the formation of liquid crystal phases (LCPs) with the help of a small-angle X-ray scattering (SAXS) analysis.
纳米颗粒自组装成复杂的超结构极具挑战性，这通常依赖于后组织技术或预先存在的模板，如多肽链、DNA或外部刺激。这种自组装过程通常会导致密堆积结构。在此，已证明在精心设计的无模板反应条件下，硫化镉量子点（QDs）能够被合成并同时自组装成复杂的超结构，而不影响单个量子点的性质。通过基于化学的方法获得的硫化镉量子点超结构表现出源自陷阱态的斯托克斯位移光致发光（PL）。值得注意的是，超结构的PL衰减呈现单指数特征。这种行为对于合成的超结构来说是不寻常的，表明陷阱态被限制在一个狭窄的范围内。借助小角X射线散射（SAXS）分析，通过液晶相（LCPs）的形成来解释这些超结构的生长机制。
