Luminescence and Morphological Kinetics of Functionalized ZnS Colloidal Nanocrystals

Abstract

This paper reports functionalized zinc sulphide (ZnS) semiconductor nanocrystals (quantum dots, approx., 2.5 nm) which are an important building block in self-assembled nanostructures. ZnS is functionalized by organic stabilizer Thio glycolic acid (TGA). The samples have been synthesized by colloidal technique at relatively low temperature (below 100• C) at an atmospheric pressure of 10 −3 torr. Manganese (Mn) doping ions have been incorporated (doped) in ZnS host lattice and observed its effect on growth morphology and optical properties of ZnS colloidal nanocrystals. By XRD, SEM, TEM, and PL, the obtained cubic phase nanosized TGA-capped ZnS materials were characterized. The morphology of ZnS obtained at different temperatures are analyzed by SEM. The crystallite size of the ZnS nanoparticles was estimated from the X-ray diffraction pattern by using Scherrer's formula (approximately 2.5 nm) which is confirmed by TEM. The estimated bandgap value of ZnS NC's by (αhύ) 2 versus hύ plot was 4.89 eV. Gaussian fitting curve in photoluminescence (PL) spectra indicated room temperature emission wavelength range from 300 to 500 nm in undoped and Mn-doped ZnS, with different emission peak intensities, and suggested the wide band emission colours in visible and near UV region which has wider applications in optical devices.

ZnS/Ethylenediamine Hybrid Micrometer Sheets Synthesized<i> In Situ</i> on Zn Foils

“…Bulk ZnS has a band gap absorption at about 320 nm. [16] Based on our former reported results, the blue shift might come from the quantum confinement effects caused by internal sub-nanostructures of the ZnS/ethylenediamine microsheets had. [13][14][15]…”

Analysis and Design of an Object-Independent Superlens

“…Subsequently, ZnS with higher permittivity is selected as a dielectric. The permittivity of ZnS is 5.52 and it has many practical applications in the visible range [25,26]. For the silver-ZnS couple, the impedance matching condition results in a reasonable value for the η given by η = 4.2.…”

Application of thiol capped ZnS quantum dots as a fluorescence probe for determination of tetracycline residues

“…The photoluminescence of ZnS quantum dots is complex, as it is influenced by several synthetic conditions like refluxing time, capping agent and its concentration, reaction temperature, agitation etc. [51,52] and crystal sizes and shapes [53,54]. It is reported in literature that the emission spectrum of ZnS can be adjusted in a very broad range from 300 nm to 550 nm [55].…”