Photoluminescence-based correlation of semiconductor electric field thickness with adsorbate Hammett substituent constants. Adsorption of aniline derivatives onto cadmium selenide

Easily prepared high-quantum-yield CdS quantum dots in water using hyperbranched polyethylenimine as modifier

“…However, previous research indicated that polyamidoamine dendrimers and PEI reduced the QY of QD [29,30]. We adopted the strategy that PEI interacted with performed CdS (mercaptoacetic acid as surfactant), since PEI is a kind of Lewis base and Lewis bases cause PL enhancement [21][22][23][24][25][26]. The results come out as expected.…”

“…This shell can be designed carefully to obtain QY close to 85% [17,18]. A second, common approach applies proper surface passivation ligands to eliminate surface traps aroused by dangling bonds, causing PL enhancement [19][20][21][22][23][24][25][26]. In this paper the second approach is chosen and the synthesis and PL properties of CdS nanocrystal are described.…”

Development of an Anion Probe: Detection of Sulfate Ion by Two-Photon Fluorescence of Gold Nanoparticles

“…These facts suggest that the fluorescence seems to come from AuNPs only. The formation of aggregated species 36 and change in polarity at the surface of nanoparticles 28 are known enhancement factors of TP fluorescence. Aggregation of AuNPs is generally accompanied with a change in extinction spectra.…”

“…27 It is also known that the fluorescence related to the hole-electron recombination process in nanoparticles is influenced by the polarity of surface molecules. 28,29 Anion receptors in combination with photosensitive nanoparticles will be a good candidate for ion indicators. Based on this idea, selective detection for sulfate ion in an aqueous solution with the enhancement of the TP fluorescence of AuNPs was developed.…”

Influence of surfactant structures in luminescence enhancement dynamics during nucleation and growth of aqueous ZnS nanoparticles and their photoactivation due to illumination with UV/visible light

“…We therefore assign the broad emission band mainly to zinc vacancies with some contributions from interstitial zinc and sulfur atoms. Moreover the energetic distributions and electron occupancy of semiconductor surface states can be altered by adsorption of some molecular species [25]. Therefore, we believe that in addition to limiting the growth of NPs, the adsorbed surfactants act as surface passivating agent to eliminate nonradiative recombination channels caused by dangling bonds (due to the absence of some of the lattice atoms), thereby modifying the surface energy states, making electronic transitions more favorable for radiative recombination and hence enhance the PL emission of the ZnS NPs as compared to their bare counterparts.…”