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Bright, stable, and water-soluble CuInS2/ZnS nanocrystals passivated by cetyltrimethylammonium bromide.

Lee J, Han CS - Nanoscale Res Lett (2015)

Bottom Line: As the result, a high quantum yield (QY) of 56.0% and excellent photostability were acquired in aqueous media.For removing excessive surfactants, cold treatment (4°C) of the CTAB-water solution was adopted to prevent further agglomeration of CIS/ZnS NCs, which could secure high stability over 6 months (less 2% reduction in QY).The high stability and PL of water soluble CTAB-CIS/ZnS NCs suggest their potential in nanoelectronics and bioapplications.

View Article: PubMed Central - PubMed

Affiliation: School of Mechanical Engineering, Korea University, 145 Anam-ro, Seoul, Korea.

ABSTRACT
We report a highly bright and stable aqueous dispersion of CuInS2/ZnS (CIS/ZnS) nanocrystals (NCs) using surfactant-assisted microemulsion and cold treatment. CIS/ZnS NCs were facilely synthesized via a stepwise, consecutive hybrid flow reactor approach. To stabilize the optical properties of hydrophobic CIS/ZnS NCs, cetyltrimethylammonium bromide (CTAB) was chosen as a matrix for aqueous phase transfer. As the result, a high quantum yield (QY) of 56.0% and excellent photostability were acquired in aqueous media. For removing excessive surfactants, cold treatment (4°C) of the CTAB-water solution was adopted to prevent further agglomeration of CIS/ZnS NCs, which could secure high stability over 6 months (less 2% reduction in QY). The optical features and structure of the obtained CTAB stabilized CIS/ZnS (CTAB-CIS/ZnS) NCs have been characterized by UV-vis and photoluminescence (PL) spectroscopies, XRD, XPS, EDX, and TEM. The high stability and PL of water soluble CTAB-CIS/ZnS NCs suggest their potential in nanoelectronics and bioapplications.

No MeSH data available.


Spray process and photos of samples under irradiation of 254-nm light. (a) Scheme of spray process and photos of films coated on glass substrates; (b) CTAB-CIS/ZnS NC film (water) and (c) CIS/ZnS NC film (toluene).
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Fig7: Spray process and photos of samples under irradiation of 254-nm light. (a) Scheme of spray process and photos of films coated on glass substrates; (b) CTAB-CIS/ZnS NC film (water) and (c) CIS/ZnS NC film (toluene).

Mentions: The NC films have been prepared by a spray coating method on glass surface. Figure 7a shows the spray process. Heat-treatment of the substrates plays an important role to obtain homogeneous films. The substrates were heated to 50°C, followed by coating NCs on them, where the solvent was steadily evaporated to form a film on the substrate surface. Such low temperature did not affect the PL efficiency of the NCs during the spray process [32]. Figure 7b,c shows photos of samples under irradiation of 254 nm light. Figure 7b shows the photo of film with water soluble CTAB-CIS/ZnS NCs. The NCs were uniformly dispersed in the film without aggregation. Homogeneous film was coated on the glass substrate. The bright PL was observed. However, the fluorescence of the oil soluble CIS/ZnS NC film looks like a heterogeneous surface (Figure 7c), which indicates that the NCs dissolve in the toluene if they are not heated at a high temperature during spray process [33]. As a result, the CTAB-CIS/ZnS NC film can be applied to biosensing assemblies, biomedical devices, and light-emitting devices.Figure 7


Bright, stable, and water-soluble CuInS2/ZnS nanocrystals passivated by cetyltrimethylammonium bromide.

Lee J, Han CS - Nanoscale Res Lett (2015)

Spray process and photos of samples under irradiation of 254-nm light. (a) Scheme of spray process and photos of films coated on glass substrates; (b) CTAB-CIS/ZnS NC film (water) and (c) CIS/ZnS NC film (toluene).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
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getmorefigures.php?uid=PMC4385304&req=5

Fig7: Spray process and photos of samples under irradiation of 254-nm light. (a) Scheme of spray process and photos of films coated on glass substrates; (b) CTAB-CIS/ZnS NC film (water) and (c) CIS/ZnS NC film (toluene).
Mentions: The NC films have been prepared by a spray coating method on glass surface. Figure 7a shows the spray process. Heat-treatment of the substrates plays an important role to obtain homogeneous films. The substrates were heated to 50°C, followed by coating NCs on them, where the solvent was steadily evaporated to form a film on the substrate surface. Such low temperature did not affect the PL efficiency of the NCs during the spray process [32]. Figure 7b,c shows photos of samples under irradiation of 254 nm light. Figure 7b shows the photo of film with water soluble CTAB-CIS/ZnS NCs. The NCs were uniformly dispersed in the film without aggregation. Homogeneous film was coated on the glass substrate. The bright PL was observed. However, the fluorescence of the oil soluble CIS/ZnS NC film looks like a heterogeneous surface (Figure 7c), which indicates that the NCs dissolve in the toluene if they are not heated at a high temperature during spray process [33]. As a result, the CTAB-CIS/ZnS NC film can be applied to biosensing assemblies, biomedical devices, and light-emitting devices.Figure 7

Bottom Line: As the result, a high quantum yield (QY) of 56.0% and excellent photostability were acquired in aqueous media.For removing excessive surfactants, cold treatment (4°C) of the CTAB-water solution was adopted to prevent further agglomeration of CIS/ZnS NCs, which could secure high stability over 6 months (less 2% reduction in QY).The high stability and PL of water soluble CTAB-CIS/ZnS NCs suggest their potential in nanoelectronics and bioapplications.

View Article: PubMed Central - PubMed

Affiliation: School of Mechanical Engineering, Korea University, 145 Anam-ro, Seoul, Korea.

ABSTRACT
We report a highly bright and stable aqueous dispersion of CuInS2/ZnS (CIS/ZnS) nanocrystals (NCs) using surfactant-assisted microemulsion and cold treatment. CIS/ZnS NCs were facilely synthesized via a stepwise, consecutive hybrid flow reactor approach. To stabilize the optical properties of hydrophobic CIS/ZnS NCs, cetyltrimethylammonium bromide (CTAB) was chosen as a matrix for aqueous phase transfer. As the result, a high quantum yield (QY) of 56.0% and excellent photostability were acquired in aqueous media. For removing excessive surfactants, cold treatment (4°C) of the CTAB-water solution was adopted to prevent further agglomeration of CIS/ZnS NCs, which could secure high stability over 6 months (less 2% reduction in QY). The optical features and structure of the obtained CTAB stabilized CIS/ZnS (CTAB-CIS/ZnS) NCs have been characterized by UV-vis and photoluminescence (PL) spectroscopies, XRD, XPS, EDX, and TEM. The high stability and PL of water soluble CTAB-CIS/ZnS NCs suggest their potential in nanoelectronics and bioapplications.

No MeSH data available.