Color-Tunable ZnO Quantum Dots Emitter: Size Effect Study and a Kinetic Control of Crystallization

Abstract

From the viewpoint of chemical reaction kinetics, the particle size of ZnO quantum dots (QDs) can be well designed upon their reaction tunable crystallization processes in solution, the visible emission of these QDs is tunable from blue to yellow. Some key factors such as the reaction time, temperature, the content of OH − and exotic ion Mg 2+ were comprehensively studied, which finely control the particle size of ZnO QDs and can be easily monitored by UV-vis spectral variations. All results indicate that the particle size of ZnO QDs increases with prolonging the reaction time, increasing the reaction temperature, and increasing the content of OH − , however, the introduction of the exotic ion Mg 2+ can effectively decrease the particle size of ZnO QDs during their crystallization.

Dual role of the reactant MOH (M=Li, Na or K) in the growth of ZnO quantum dots under a sol–gel process: promoter and inhibitor

“…It has been widely reported that higher reaction temperature will lead to the larger particles size due to the faster growth rate. 22,26,35 Besides, the growth rate can also be enhanced with increasing carbon chain length of alcoholic solvent due to the inuence of solvent viscosity, surface energy and the solubility of ZnO. 36 Consequently, bigger ZnO QDs tend to be formed in an alcoholic solvent with longer carbon chain length.…”

“…23,24 This explanation seems to be unreasonable when considering the previous conclusion from Sarma et al, because they claimed that besides Li + ions, both of Na + and K + ions can also hinder the growth of ZnO QDs. 20,25 More puzzlingly, when using KOH as the reactant, the particle size of ZnO QDs increases with increasing the amount of OH À ions, 26 showing a quite different behavior with LiOH. Therefore, there still lacks a comprehensive investigation and especially a self-consistent explanation that can apply for all above cases.…”

Effect of Triethanolamine on Zinc Oxide Nanoparticles

“…The morphology of ZnO structures can also be manipulated by using different zinc salts. 23 Color tunable (from blue to yellow) ZnO quantum dots were prepared by Zhang et al 24 by tuning the crystallization process in the solution.…”

2-Aminoethanol-mediated wet chemical synthesis of ZnO nanostructures

“…In the past few years, ZnO-based nanostructured materials have emerged as the first-choice materials not only for semiconductor devices such as sensors (Chougule et al 2012;Afzal et al 2012) and solar cells (Kim et al 2013;Patra et al 2014), but also in other fields as UV emitters (Zhang et al 2013), optical waveguides (Jiang et al 2012), and biomedical (Yang et al 2012) and optoelectronic devices (Zhang et al 2012). The nontoxic nature, low cost, stability, easy processability, and nanostructuring are the chief distinctions of ZnO (Schmidt-Mende and MacManusDriscoll 2007).…”