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Morphological variations in cadmium sulfide nanocrystals without phase transformation.

Dhage SR, Colorado HA, Hahn T - Nanoscale Res Lett (2011)

Bottom Line: Environmentally stable and highly crystalline CdS nanorods have been obtained via a chemical bath method.The prepared CdS nanorods have been characterized by X-ray powder diffraction, TEM, UV-Vis spectroscopy, and photoluminescence spectroscopy.The importance of this phenomenon is vital for the potential application for CdS such as smart materials.

View Article: PubMed Central - HTML - PubMed

Affiliation: Mechanical and Aerospace Engineering Department, University of California, Los Angeles, CA 90095, USA. sanjay.dhage@gmail.com.

ABSTRACT
A very novel phenomenon of morphological variations of cadmium sulfide (CdS) nanorods under the transmission electron microscopy (TEM) beam was observed without structural phase transformation. Environmentally stable and highly crystalline CdS nanorods have been obtained via a chemical bath method. The energy of the TEM beam is believed to have a significant influence on CdS nanorods and may melt and transform them into smaller nanowires. Morphological variations without structural phase transformation are confirmed by recording selected area electron diffraction at various stages. The prepared CdS nanorods have been characterized by X-ray powder diffraction, TEM, UV-Vis spectroscopy, and photoluminescence spectroscopy. The importance of this phenomenon is vital for the potential application for CdS such as smart materials.

No MeSH data available.


Related in: MedlinePlus

Photoluminescence spectra of CdS nanorods. Inset: UV-Visible absorption spectra of the CdS nanoparticles at 400 to 700 nm.
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Figure 4: Photoluminescence spectra of CdS nanorods. Inset: UV-Visible absorption spectra of the CdS nanoparticles at 400 to 700 nm.

Mentions: The optical properties of the as-synthesized CdS nanorods were then studied. The room-temperature absorption spectra obtained from the dispersed solutions of CdS nanorods are shown in Figure 4 (inset). The absorption peaks for nanorods are located at 496 nm, which is blue-shifted from the bulk band gap value of CdS (517 nm) due to the quantum confinement effect. The PL spectra of dispersed CdS nanorods are shown in Figure 4, with an excitation at 390 nm. It is noteworthy that the PL spectrum shows an intense PL peak at 449 nm with two small peaks at 468 and 503 nm. The literature [24] reports that the recombination of excitons and/or shallowly trapped electron/hole pairs that causes the band edge luminescence (narrow bands between 450 and 500 nm). These PL emissions indicate that after light absorption in the CdS nanorods, the photogenerated electron/hole pair was trapped, with emission at 467 nm upon their recombination.


Morphological variations in cadmium sulfide nanocrystals without phase transformation.

Dhage SR, Colorado HA, Hahn T - Nanoscale Res Lett (2011)

Photoluminescence spectra of CdS nanorods. Inset: UV-Visible absorption spectra of the CdS nanoparticles at 400 to 700 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211837&req=5

Figure 4: Photoluminescence spectra of CdS nanorods. Inset: UV-Visible absorption spectra of the CdS nanoparticles at 400 to 700 nm.
Mentions: The optical properties of the as-synthesized CdS nanorods were then studied. The room-temperature absorption spectra obtained from the dispersed solutions of CdS nanorods are shown in Figure 4 (inset). The absorption peaks for nanorods are located at 496 nm, which is blue-shifted from the bulk band gap value of CdS (517 nm) due to the quantum confinement effect. The PL spectra of dispersed CdS nanorods are shown in Figure 4, with an excitation at 390 nm. It is noteworthy that the PL spectrum shows an intense PL peak at 449 nm with two small peaks at 468 and 503 nm. The literature [24] reports that the recombination of excitons and/or shallowly trapped electron/hole pairs that causes the band edge luminescence (narrow bands between 450 and 500 nm). These PL emissions indicate that after light absorption in the CdS nanorods, the photogenerated electron/hole pair was trapped, with emission at 467 nm upon their recombination.

Bottom Line: Environmentally stable and highly crystalline CdS nanorods have been obtained via a chemical bath method.The prepared CdS nanorods have been characterized by X-ray powder diffraction, TEM, UV-Vis spectroscopy, and photoluminescence spectroscopy.The importance of this phenomenon is vital for the potential application for CdS such as smart materials.

View Article: PubMed Central - HTML - PubMed

Affiliation: Mechanical and Aerospace Engineering Department, University of California, Los Angeles, CA 90095, USA. sanjay.dhage@gmail.com.

ABSTRACT
A very novel phenomenon of morphological variations of cadmium sulfide (CdS) nanorods under the transmission electron microscopy (TEM) beam was observed without structural phase transformation. Environmentally stable and highly crystalline CdS nanorods have been obtained via a chemical bath method. The energy of the TEM beam is believed to have a significant influence on CdS nanorods and may melt and transform them into smaller nanowires. Morphological variations without structural phase transformation are confirmed by recording selected area electron diffraction at various stages. The prepared CdS nanorods have been characterized by X-ray powder diffraction, TEM, UV-Vis spectroscopy, and photoluminescence spectroscopy. The importance of this phenomenon is vital for the potential application for CdS such as smart materials.

No MeSH data available.


Related in: MedlinePlus