Mechanistic Study of Amphiphilic-Assisted Self-Assembled Cadmium Sulfide Quantum Dots into 3D Superstructures

Abstract

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.

Nanostructured Porous HgSe Rod Superstructure for Photoresponsive Applications

“…Directing these building blocks either by assembly/self-assembly of nanocrystals or by decomposition of molecular template into ordered superstructures assisted by the synergistic effect of various physical forces (e.g., electrostatic interactions, van der Waals forces, and hydrogen bonds, etc.) for next-generation nanophotonics and nanoelectronics combined with fundamental understanding has been riveting. − For instance, in the case of self-assembly of nanocrystals, different attractive and repulsive forces existing between nanocrystals influence the formation of ordered structures. In the case of molecular templates, crystal packing arises as a result of noncovalent interactions. , Nevertheless, the intricate roles of interparticle and intra/intermolecular interactions existing between NCs and molecules, respectively, make it tough to estimate NC or molecular arrangements into ordered structures.…”