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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) Schematic diagram of single CuSe nanosheet-based electrical circuit for C-AFM measurement. (b) Topography and (c, d) current images of CuSe nanosheet are obtained simultaneously under the C-AFM mode. The applied bias voltage is (c) 100 mV and (d) −100 mV. (e, f) Spatial profiles of the current along corresponding lines in the C-AFM images (c, d).
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f7: (a) Schematic diagram of single CuSe nanosheet-based electrical circuit for C-AFM measurement. (b) Topography and (c, d) current images of CuSe nanosheet are obtained simultaneously under the C-AFM mode. The applied bias voltage is (c) 100 mV and (d) −100 mV. (e, f) Spatial profiles of the current along corresponding lines in the C-AFM images (c, d).

Mentions: To reveal the intrinsic electrical properties, the I-V characteristics of single CuSe NS is explored and the current distribution is mapped by conductive AFM (C-AFM), which is an effective technique to probe local conduction with nanoscale spatial resolution. Fig. 7a shows a schematic diagram of single CuSe NS-based AFM electrical circuit, in which ITO is used as the bottom electrode. The electrical characterization is applied in contact mode with a conductive diamond tip. The bias voltage is applied to the sample while keeping the tip grounded. Fig. 7b–f show topography and typical C-AFM images of single CuSe NS by point-to-point tip scanning. The targeted CuSe NS has uniform thickness and smooth surface (Fig. S9). By applying a dc bias voltage of 100 mV, the currents in fringe region can reach ~10 nA, while no obvious currents occurs in the middle region (Fig. 7c, e). The same local conduction currents are also observed when the bias voltage is reversed (Fig. 7d, f). The above observation indicates a substantial conductivity difference between the middle and fringe regions of hexagonal CuSe NS.


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) Schematic diagram of single CuSe nanosheet-based electrical circuit for C-AFM measurement. (b) Topography and (c, d) current images of CuSe nanosheet are obtained simultaneously under the C-AFM mode. The applied bias voltage is (c) 100 mV and (d) −100 mV. (e, f) Spatial profiles of the current along corresponding lines in the C-AFM images (c, d).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f7: (a) Schematic diagram of single CuSe nanosheet-based electrical circuit for C-AFM measurement. (b) Topography and (c, d) current images of CuSe nanosheet are obtained simultaneously under the C-AFM mode. The applied bias voltage is (c) 100 mV and (d) −100 mV. (e, f) Spatial profiles of the current along corresponding lines in the C-AFM images (c, d).
Mentions: To reveal the intrinsic electrical properties, the I-V characteristics of single CuSe NS is explored and the current distribution is mapped by conductive AFM (C-AFM), which is an effective technique to probe local conduction with nanoscale spatial resolution. Fig. 7a shows a schematic diagram of single CuSe NS-based AFM electrical circuit, in which ITO is used as the bottom electrode. The electrical characterization is applied in contact mode with a conductive diamond tip. The bias voltage is applied to the sample while keeping the tip grounded. Fig. 7b–f show topography and typical C-AFM images of single CuSe NS by point-to-point tip scanning. The targeted CuSe NS has uniform thickness and smooth surface (Fig. S9). By applying a dc bias voltage of 100 mV, the currents in fringe region can reach ~10 nA, while no obvious currents occurs in the middle region (Fig. 7c, e). The same local conduction currents are also observed when the bias voltage is reversed (Fig. 7d, f). The above observation indicates a substantial conductivity difference between the middle and fringe regions of hexagonal CuSe NS.

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.