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Facile microwave-assisted synthesis of Klockmannite CuSe nanosheets and their exceptional electrical properties.

Liu YQ, Wang FX, Xiao Y, Peng HD, Zhong HJ, Liu ZH, Pan GB - Sci Rep (2014)

Bottom Line: This is ascribed to the quantum size effect of NS and the presence of Schottky barrier.In addition, the influence of the molar ratio of Cu(2+)/SeO2, reaction temperature, and reaction time on the growth of CuSe NSs is explored.The template effect of oleylamine and the intrinsic crystal nature of CuSe NS are proposed to account for the growth of hexagonal CuSe NSs.

View Article: PubMed Central - PubMed

Affiliation: Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, 215123 Suzhou, P. R. China.

ABSTRACT
Klockmannite copper selenide nanosheets (CuSe NSs) are synthesized by a facile microwave-assisted method and fully characterized. The nanosheets have smooth surface and hexagonal shape. The lateral size is 200-500 nm × 400-800 nm and the thickness is 55 ± 20 nm. The current-voltage characteristics of CuSe NS films show unique Ohmic and high-conducting behaviors, comparable to the thermally-deposited gold electrode. The high electrical conductivity of CuSe NSs implies their promising applications in printed electronics and nanodevices. Moreover, the local electrical variation is observed, for the first time, within an individual CuSe NS at low bias voltages (0.1 ~ 3 V) by conductive atomic force microscopy (C-AFM). This is ascribed to the quantum size effect of NS and the presence of Schottky barrier. In addition, the influence of the molar ratio of Cu(2+)/SeO2, reaction temperature, and reaction time on the growth of CuSe NSs is explored. The template effect of oleylamine and the intrinsic crystal nature of CuSe NS are proposed to account for the growth of hexagonal CuSe NSs.

No MeSH data available.


(a) FE-SEM and (b) TEM images of as-prepared CuSe nanosheets. (c) HR-TEM lattice image of a single CuSe nanosheet. (d) The fast Fourier transform pattern taken from HR-TEM image (Fig. 2c).
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f2: (a) FE-SEM and (b) TEM images of as-prepared CuSe nanosheets. (c) HR-TEM lattice image of a single CuSe nanosheet. (d) The fast Fourier transform pattern taken from HR-TEM image (Fig. 2c).

Mentions: The morphology and size of CuSe NSs are investigated by field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). Fig. 2a shows a typical FE-SEM image of CuSe NSs, revealing hexagonal and quasi-hexagonal shapes, which have smooth surfaces (Fig. 2b). The average lateral size of CuSe NSs extracted from SEM image is 200–500 nm × 400–800 nm, while the thickness analyzed by atomic force microscopy (AFM, Fig. S1) is 55 ± 20 nm. Fig. 2c shows a typical high-resolution (HR) TEM image of single CuSe NS, revealing the well-resolved 2D lattice fringes. The values of 3.41 and 3.41 Å match well with the inter-planar d-spacing of the (100) and (010) planes of klockmannite CuSe, respectively. The intersection angle of ~120° is identical to the theoretical value between the (100) and (010) planes of klockmannite CuSe. The fast Fourier transform pattern (Fig. 2d) taken from the HR-TEM image (Fig. 2c) also implies the single-crystalline hexagonal structure with the surface is normally oriented along the [001] direction. The above results are consistent with the preferable [006] orientation observed by XRD (Fig. 1a). In addition, the energy-dispersive X-ray spectrum (EDS, Fig. S2) only reveals two strong peaks of Cu and Se elements besides the peak of Si substrate. The quantitative EDS analysis shows that the atom ratio of Cu and Se is close to the intrinsic 1:1 stoichiometry, implying the homogeneous purity of CuSe NSs.


Facile microwave-assisted synthesis of Klockmannite CuSe nanosheets and their exceptional electrical properties.

Liu YQ, Wang FX, Xiao Y, Peng HD, Zhong HJ, Liu ZH, Pan GB - Sci Rep (2014)

(a) FE-SEM and (b) TEM images of as-prepared CuSe nanosheets. (c) HR-TEM lattice image of a single CuSe nanosheet. (d) The fast Fourier transform pattern taken from HR-TEM image (Fig. 2c).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126004&req=5

f2: (a) FE-SEM and (b) TEM images of as-prepared CuSe nanosheets. (c) HR-TEM lattice image of a single CuSe nanosheet. (d) The fast Fourier transform pattern taken from HR-TEM image (Fig. 2c).
Mentions: The morphology and size of CuSe NSs are investigated by field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). Fig. 2a shows a typical FE-SEM image of CuSe NSs, revealing hexagonal and quasi-hexagonal shapes, which have smooth surfaces (Fig. 2b). The average lateral size of CuSe NSs extracted from SEM image is 200–500 nm × 400–800 nm, while the thickness analyzed by atomic force microscopy (AFM, Fig. S1) is 55 ± 20 nm. Fig. 2c shows a typical high-resolution (HR) TEM image of single CuSe NS, revealing the well-resolved 2D lattice fringes. The values of 3.41 and 3.41 Å match well with the inter-planar d-spacing of the (100) and (010) planes of klockmannite CuSe, respectively. The intersection angle of ~120° is identical to the theoretical value between the (100) and (010) planes of klockmannite CuSe. The fast Fourier transform pattern (Fig. 2d) taken from the HR-TEM image (Fig. 2c) also implies the single-crystalline hexagonal structure with the surface is normally oriented along the [001] direction. The above results are consistent with the preferable [006] orientation observed by XRD (Fig. 1a). In addition, the energy-dispersive X-ray spectrum (EDS, Fig. S2) only reveals two strong peaks of Cu and Se elements besides the peak of Si substrate. The quantitative EDS analysis shows that the atom ratio of Cu and Se is close to the intrinsic 1:1 stoichiometry, implying the homogeneous purity of CuSe NSs.

Bottom Line: This is ascribed to the quantum size effect of NS and the presence of Schottky barrier.In addition, the influence of the molar ratio of Cu(2+)/SeO2, reaction temperature, and reaction time on the growth of CuSe NSs is explored.The template effect of oleylamine and the intrinsic crystal nature of CuSe NS are proposed to account for the growth of hexagonal CuSe NSs.

View Article: PubMed Central - PubMed

Affiliation: Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, 215123 Suzhou, P. R. China.

ABSTRACT
Klockmannite copper selenide nanosheets (CuSe NSs) are synthesized by a facile microwave-assisted method and fully characterized. The nanosheets have smooth surface and hexagonal shape. The lateral size is 200-500 nm × 400-800 nm and the thickness is 55 ± 20 nm. The current-voltage characteristics of CuSe NS films show unique Ohmic and high-conducting behaviors, comparable to the thermally-deposited gold electrode. The high electrical conductivity of CuSe NSs implies their promising applications in printed electronics and nanodevices. Moreover, the local electrical variation is observed, for the first time, within an individual CuSe NS at low bias voltages (0.1 ~ 3 V) by conductive atomic force microscopy (C-AFM). This is ascribed to the quantum size effect of NS and the presence of Schottky barrier. In addition, the influence of the molar ratio of Cu(2+)/SeO2, reaction temperature, and reaction time on the growth of CuSe NSs is explored. The template effect of oleylamine and the intrinsic crystal nature of CuSe NS are proposed to account for the growth of hexagonal CuSe NSs.

No MeSH data available.