Cu-Catalyzed Synthesis of CdZnSe–CdZnS Alloy Quantum Dots with Highly Tunable Emission

Abstract

Fabrication of quantum dots (QDs) with emission covering a wide spectral region has been persistently intriguing because of their potentials in a range of practical applications such as biological labeling and imaging, solar cells, light-emitting diodes, and next-generation displays. In this work, we report the synthesis of CdZnSe–CdZnS core–shell alloy QDs through a Cu-catalyzed solid solution alloying strategy starting from CdSe–CdS core–shell QDs. The resulting CdZnSe–CdZnS alloy QDs exhibit emission profiles covering a wide wavelength range of 470–650 nm while maintaining high photoluminescence quantum yields. In addition, high morphological uniformity of the starting CdSe–CdS QDs can be largely retained in the final alloy QDs. We attribute this alloying process to the high mobility nature of Cu cations in Cd-chalcogenide crystals at elevated reaction temperatures, which allows Cu cations to act as transporting agents to transfer a Zn component into the CdSe–CdS QDs while maintaining the particle integrity. We show that this unique alloying strategy is independent of the shape of the starting QDs and can also be applied to the synthesis of CdZnSe–CdZnS nanorods. We anticipate that our study will instigate the synthesis of various high-quality alloy QDs and other alloy nanocrystals beyond what can be achieved currently.

Carrier Dynamics in Alloyed Chalcogenide Quantum Dots and Their Light‐Emitting Devices

“…Through the regulation of this method, the practical PL range of QDs can be expanded for a variety of biological applica-tions. In 2019, Chen's group [87] reported a new way to fabricate CdZnSe/CdZnS core/shell alloyed QDs by using Cu cations as the transporting catalysts to effectively transfer a Zn component into CdSe/CdS core/shell QDs. The schematic illustration for Cu-induced alloying process is shown in Figure 1c.…”

“…c) Schematic illustration for Cu-induced alloying process during the synthesis of CdZnSe/CdZnS core/shell alloy QDs. Reproduced with permission [87]. Copyright 2019, American Chemical Society.…”

Silver Nanomaterials for Wound Dressing Applications

“…The level of resistance, especially against traditional antibiotics (for example, methicillin-resistant Staphylococcus aureus [ 8 ], penicillin-resistant Enterococcus faecalis [ 9 ] or multiresistant Mycobacterium tuberculosis [ 10 ]) is still increasing, and the rising incidence of antimicrobial resistance among pathogenic bacteria is one of the greatest healthcare challenges facing humanity today [ 11 ]. Thus, new approaches to overcome bacterial resistance are being tried, comprising by using plant extracts [ 12 ] or a combination of antibiotics and other antibacterial materials [ 13 ], especially nanomaterials, which comprise unary [ 14 ], binary (AgAu, AgPt NPs) [ 15 , 16 ] or multicomponent materials (CdZnSe-CdZnS nanoalloy) [ 17 ]. Nanotechnology is nowadays a flourishing scientific field, which associates nanoparticles with extraordinary functions and size-dependent physicochemical properties, differing significantly from the macroscopic forms of these elements.…”

Rational Design and Synthesis of Highly Luminescent Multinary Cu‐In‐Zn‐S Semiconductor Nanocrystals with Tailored Nanostructures

“…In the past tens of years, colloidal semiconductor NCs have attracted much attention due to their unique optical and electrical properties as well as their promising applications in light‐emitting diodes (LEDs), photovoltaic cells, and biological labels . However, the best studied II–VI and IV–VI group semiconductor NCs contain toxic heavy metals, such as cadmium (Cd) and lead (Pb) elements, which restrict their further industrial applications.…”