Synthesis of ZnO quantum dots and their agglomeration mechanisms along with emission spectra based on ageing time and temperature

Abstract

The ZnO quantum dots (QDs) were synthesized with improved chemical solution method. The size of the ZnO QDs is exceedingly uniform with a diameter of approximately 4.8 nm, which are homogeneously dispersed in ethanol. The optical absorption edge shifts from 370 nm of bulk material to 359 nm of QD materials due to the quantum size effect, while the photoluminescence peak shifts from 375 nm to 387 nm with the increase of the density of ZnO QDs. The stability of ZnO QDs was studied with different dispersion degrees at 0 • C and at room temperature of 25 • C. The agglomeration mechanisms and their relationship with the emission spectra were uncovered for the first time. With the ageing of ZnO QDs, the agglomeration is aggravated and the surface defects increase, which leads to the defect emission.

InP/ZnSeS/ZnS Quantum Dot-Embedded Alumina Microbeads for Color-by-Blue Displays

“…The average lifetimes (τ avg ) of the four kinds of pristine C-QD and treated QD solution samples seem to be very similar (Table S3). These results indicate that unwanted agglomeration and surface oxidation did not take place during metal alkoxide ligand complexing and shell passivation material doping treatments . The pristine C-QD microbead powder shows the shortest decay time (22.7 ns) among all four QD-embedded microbead powders (Table S4).…”

“…These results indicate that unwanted agglomeration and surface oxidation did not take place during metal alkoxide ligand complexing and shell passivation material doping treatments. 47 The pristine C-QD microbead powder shows the shortest decay time (22.7 ns) among all four QDembedded microbead powders (Table S4). This slight increase of decay time confirms that the Hf-alkoxide complex interlayer or Al-doped shell provides a protection layer against the harsh E-spray environment.…”

Novel Surface Modification of ZnO QDs for Paclitaxel-Targeted Drug Delivery for Lung Cancer Treatment

“…ZnO QD synthesis was based on a previous paper. 38 Specifically, zinc acetate (0.1 mol, Sigma Aldrich, 98%) was refluxed in ethanolic solution (50 mL, VWR) for 2 hours. After that, the zinc acetate solution (10 mL) was diluted with ethanol (20 mL), and LiOH powder (2.8 mmol, Sigma Aldrich, 99%) was added to the previous solution with magnetic stirring.…”

SnS 2 quantum dots: Facile synthesis, properties, and applications in ultraviolet photodetector

“…Low-cost solution-based synthesis of colloidal semiconductor QDs has attracted increasing attention due to their applications in photodetectors. [14] The colloidal preparation methods of SnS 2 QDs include liquid-phase exfoliation (LPE), [15] solution thermal synthesis, [12] hot injection, [13,16] and wet chemistry methods. [17] The QDs prepared by colloidal chemistry are also known as colloidal quantum dots (CQDs).…”