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One-step synthesis of PbSe-ZnSe composite thin film.

Abe S - Nanoscale Res Lett (2011)

Bottom Line: The XRD result reveals that the solubility limit of Pb in ZnSe is quite narrow, less than 1 mol%, with obvious phase-separation in the composite thin films.A nanoscale elemental mapping of the film containing 5 mol% PbSe indicates that isolated PbSe nanocrystals are dispersed in the ZnSe matrix.The use of a phase-separating PbSe-ZnSe system and HWD techniques enables simple production of the composite package.

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Affiliation: Research Institute for Electric and Magnetic Materials, Sendai 982-0807, Japan. abe@denjiken.ne.jp.

ABSTRACT
This study investigates the preparation of PbSe-ZnSe composite thin films by simultaneous hot-wall deposition (HWD) from multiple resources. The XRD result reveals that the solubility limit of Pb in ZnSe is quite narrow, less than 1 mol%, with obvious phase-separation in the composite thin films. A nanoscale elemental mapping of the film containing 5 mol% PbSe indicates that isolated PbSe nanocrystals are dispersed in the ZnSe matrix. The optical absorption edge of the composite thin films shifts toward the low-photon-energy region as the PbSe content increases. The use of a phase-separating PbSe-ZnSe system and HWD techniques enables simple production of the composite package.

No MeSH data available.


Direct observation of PbSe-ZnSe composite thin film containing 5 mol% PbSe. (a) Bright-field TEM image. (b) Bright-field image of STEM mode. (c) Elemental mapping of Zn (red), (d) Se (blue), and (e) Pb (green).
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Figure 4: Direct observation of PbSe-ZnSe composite thin film containing 5 mol% PbSe. (a) Bright-field TEM image. (b) Bright-field image of STEM mode. (c) Elemental mapping of Zn (red), (d) Se (blue), and (e) Pb (green).

Mentions: Figure 4a presents a bright-field TEM image of the PbSe-ZnSe composite thin film containing 5 mol% PbSe. Dark isolated grains with sizes of 25 to 50 nm are seen dispersed along the grain boundary of the bright area. Figure 4b-e presents an STEM-EDX elemental mapping of the sample through X-ray detection of Zn K (red), Se K (blue), and Pb L (green). Similar morphology is also seen in the bright-field STEM image (Figure 4b)). The dark grains indicate the absence of elemental Zn (Figure 4c) and the presence of Se and Pb (Figure 4d, e). It is thus determined that the dark grains are nanocrystalline PbSe. The other region is widely covered with the elements Zn and Se (Figure 4c,d), reasonably assumed to compose ZnSe. It is therefore determined that isolated PbSe nanocrystals are dispersed in the ZnSe matrix. The nanocrystals are estimated to be sufficiently small to exhibit the quantum-size effect because of the exciton Bohr radius of 46 nm in PbSe [13].


One-step synthesis of PbSe-ZnSe composite thin film.

Abe S - Nanoscale Res Lett (2011)

Direct observation of PbSe-ZnSe composite thin film containing 5 mol% PbSe. (a) Bright-field TEM image. (b) Bright-field image of STEM mode. (c) Elemental mapping of Zn (red), (d) Se (blue), and (e) Pb (green).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211412&req=5

Figure 4: Direct observation of PbSe-ZnSe composite thin film containing 5 mol% PbSe. (a) Bright-field TEM image. (b) Bright-field image of STEM mode. (c) Elemental mapping of Zn (red), (d) Se (blue), and (e) Pb (green).
Mentions: Figure 4a presents a bright-field TEM image of the PbSe-ZnSe composite thin film containing 5 mol% PbSe. Dark isolated grains with sizes of 25 to 50 nm are seen dispersed along the grain boundary of the bright area. Figure 4b-e presents an STEM-EDX elemental mapping of the sample through X-ray detection of Zn K (red), Se K (blue), and Pb L (green). Similar morphology is also seen in the bright-field STEM image (Figure 4b)). The dark grains indicate the absence of elemental Zn (Figure 4c) and the presence of Se and Pb (Figure 4d, e). It is thus determined that the dark grains are nanocrystalline PbSe. The other region is widely covered with the elements Zn and Se (Figure 4c,d), reasonably assumed to compose ZnSe. It is therefore determined that isolated PbSe nanocrystals are dispersed in the ZnSe matrix. The nanocrystals are estimated to be sufficiently small to exhibit the quantum-size effect because of the exciton Bohr radius of 46 nm in PbSe [13].

Bottom Line: The XRD result reveals that the solubility limit of Pb in ZnSe is quite narrow, less than 1 mol%, with obvious phase-separation in the composite thin films.A nanoscale elemental mapping of the film containing 5 mol% PbSe indicates that isolated PbSe nanocrystals are dispersed in the ZnSe matrix.The use of a phase-separating PbSe-ZnSe system and HWD techniques enables simple production of the composite package.

View Article: PubMed Central - HTML - PubMed

Affiliation: Research Institute for Electric and Magnetic Materials, Sendai 982-0807, Japan. abe@denjiken.ne.jp.

ABSTRACT
This study investigates the preparation of PbSe-ZnSe composite thin films by simultaneous hot-wall deposition (HWD) from multiple resources. The XRD result reveals that the solubility limit of Pb in ZnSe is quite narrow, less than 1 mol%, with obvious phase-separation in the composite thin films. A nanoscale elemental mapping of the film containing 5 mol% PbSe indicates that isolated PbSe nanocrystals are dispersed in the ZnSe matrix. The optical absorption edge of the composite thin films shifts toward the low-photon-energy region as the PbSe content increases. The use of a phase-separating PbSe-ZnSe system and HWD techniques enables simple production of the composite package.

No MeSH data available.