Patterning of ZnO Quantum Dot and PMMA Hybrids with a Solvent-Assisted Technique

Ultrahigh-resolution quantum dot patterning for advanced optoelectronic devices

Quantum dots have attracted significant scientific interest owing to their optoelectronic properties, which are distinct from their bulk counterparts. In order to fully utilize quantum dots for next generation devices with advanced functionalities, it is important to fabricate quantum dot colloids into dry patterns with desired feature sizes and shapes with respect to target applications. In this review, recent progress in ultrahigh-resolution quantum dot patterning technologies will be discussed, with emphasis on the characteristic advantages as well as the limitations of diverse technologies. This will provide guidelines for selecting suitable tools to handle quantum dot colloids throughout the fabrication of quantum dot based solid-state devices. Additionally, epitaxially fabricated single-particle level quantum dot arrays are discussed. These are extreme in terms of pattern resolution, and expand the potential application of quantum dots to quantum information processing.

Journey of ZnO quantum dots from undoped to rare-earth and transition metal-doped and their applications

Currently, developments in the field of quantum dots (QDs) have attracted researchers worldwide. A large variety of QDs have been discovered in the few years, which have excellent optoelectronic, antibacterial, magnetic, and other properties. However, ZnO is the single known material that can exist in the quantum state and can hold all the above properties. There is a lot of work going on in this field and we will be shorthanded if we do not accommodate this treasure at one place. This manuscript will prove to be a milestone in this noble cause. Having a tremendous potential, there is a developing enthusiasm toward the application of ZnO QDs in diverse areas. Sol-gel method being the simplest is the widely-favored synthetic method. Synthesis via this method is largely affected by a number of factors such as the reaction temperature, duration of the reaction, type of solvent, pH of the solution, and the precipitating agent. Doping enhances the optical, magnetic, anti-bacterial, anti-microbial, and other properties of ZnO QDs. However, doping elements reside mostly on the surface of the QDs. The presence of doping elements inside the core is still a major challenge for doping techniques. In this review article, we have focused on pure, rare-earth, and transition metal-doped ZnO QD properties, and the various synthetic processes and applications. Quantum confinement effect is present in nearly every aspect of the QDs. The effect of quantum confinement has also been summarized in this manuscript. Furthermore, the doping of rare earth elements and transition metal, synthetic methods for different organic molecule-capped ZnO QDs, mechanisms for reactive oxygen species (ROS) generation, drug delivery system for cancer treatment, and many more application are discussed in this paper.

Photothermal self-healing of gold nanoparticle-polystyrene hybrids

This study focused on the processing and photothermal healing of gold nanoparticle (Au NP) and polystyrene (PS) hybrid films. Effects of Au NP contents were investigated using hybrid films with the NP content from 0 to 1 wt% via a solvent-assisted approach. The as-synthesized Au NPs showed an average diameter of 4-5 nm with a face-centered cubic structure. The Au NP agglomeration deteriorated as the content increased and the interparticle distance decreased. The film transparency and flexibility also decreased with the NP content. The Au-PS films demonstrated desirable photothermal healing behaviors, which required more energy with the defect size increase. The simulated temperature distribution on the hybrid films during the photo-induced healing showed good agreement with the experimental results, with particle agglomeration degrading the healing properties. The developed hybrid films can be used in functional devices and coatings with high flexibility and healed using photon energy sources.