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Over 95% of large-scale length uniformity in template-assisted electrodeposited nanowires by subzero-temperature electrodeposition.

Shin S, Kong BH, Kim BS, Kim KM, Cho HK, Cho HH - Nanoscale Res Lett (2011)

Bottom Line: Even with highly disordered commercial porous anodic aluminum oxide template and conventional potentiostatic electrodeposition, length uniformity over 95% can be achieved when the deposition temperature is lowered down to -2.4°C.Decreased diffusion coefficient and ion concentration gradient due to the lowered deposition temperature effectively reduces ion diffusion rate, thereby favors uniform nanowire growth.Moreover, by varying the deposition temperature, we show that also the pore nucleation and the crystallinity can be controlled.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical Engineering, Yonsei University, Seoul, 120-749, Korea. hhcho@yonsei.ac.kr.

ABSTRACT
In this work, we report highly uniform growth of template-assisted electrodeposited copper nanowires on a large area by lowering the deposition temperature down to subzero centigrade. Even with highly disordered commercial porous anodic aluminum oxide template and conventional potentiostatic electrodeposition, length uniformity over 95% can be achieved when the deposition temperature is lowered down to -2.4°C. Decreased diffusion coefficient and ion concentration gradient due to the lowered deposition temperature effectively reduces ion diffusion rate, thereby favors uniform nanowire growth. Moreover, by varying the deposition temperature, we show that also the pore nucleation and the crystallinity can be controlled.

No MeSH data available.


Related in: MedlinePlus

Optical microscope images of the cross sections of the AAO template with Cu nanowires. These are grown at various deposition temperatures: (a) -2.4°C; (b) -1.5°C; (c) 0.0°C; (d) 5.2°C; (e) 11.5°C; (f) 25.6°C; (g) 45.2°C; (h) 60.5°C. (i) and (j) show large-scale view of the cross sections at -2.4°C and 60.5°C, respectively. Yellow arrows indicate empty pores.
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Figure 3: Optical microscope images of the cross sections of the AAO template with Cu nanowires. These are grown at various deposition temperatures: (a) -2.4°C; (b) -1.5°C; (c) 0.0°C; (d) 5.2°C; (e) 11.5°C; (f) 25.6°C; (g) 45.2°C; (h) 60.5°C. (i) and (j) show large-scale view of the cross sections at -2.4°C and 60.5°C, respectively. Yellow arrows indicate empty pores.

Mentions: After electrodepositing the Cu nanowires at different temperatures, the cross sections of the nanowire-embedded AAO templates were observed to determine the large-scale length uniformity. The length uniformity was determined by obtaining the average nanowire length from the nanowire growth front and dividing by the length of the template. Nanowires were sufficiently deposited with enough time so that the Cu overdeposits were fully exposed on the top surface of the template. Figure 3 shows the optical microscope images of the nanowire-embedded AAO templates with varying deposition temperature. It is clearly seen that the overall length uniformity of the Cu nanowires are significantly enhanced as the deposition temperature is decreased. At high deposition temperature condition, the growth front was shown to be very disordered and fluctuating while highly uniform growth front which is located near the top edge of the AAO template was observed at subzero centigrade temperature conditions. At 60.5°C, only about 65% of the total length of the template is filled while more than 95% of the nanowire length uniformity is achieved at -2.4°C. Considering that these samples are potentiostatically electrodeposited and the AAO template used in this work is extremely disordered, this result is remarkable. Note once again that Stacy and co-workers recently achieved about 93% of nanowire length uniformity by pulsed electrodeposition in a well-ordered homemade AAO template when the deposition temperature was between 1°C and 4°C [15].


Over 95% of large-scale length uniformity in template-assisted electrodeposited nanowires by subzero-temperature electrodeposition.

Shin S, Kong BH, Kim BS, Kim KM, Cho HK, Cho HH - Nanoscale Res Lett (2011)

Optical microscope images of the cross sections of the AAO template with Cu nanowires. These are grown at various deposition temperatures: (a) -2.4°C; (b) -1.5°C; (c) 0.0°C; (d) 5.2°C; (e) 11.5°C; (f) 25.6°C; (g) 45.2°C; (h) 60.5°C. (i) and (j) show large-scale view of the cross sections at -2.4°C and 60.5°C, respectively. Yellow arrows indicate empty pores.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211979&req=5

Figure 3: Optical microscope images of the cross sections of the AAO template with Cu nanowires. These are grown at various deposition temperatures: (a) -2.4°C; (b) -1.5°C; (c) 0.0°C; (d) 5.2°C; (e) 11.5°C; (f) 25.6°C; (g) 45.2°C; (h) 60.5°C. (i) and (j) show large-scale view of the cross sections at -2.4°C and 60.5°C, respectively. Yellow arrows indicate empty pores.
Mentions: After electrodepositing the Cu nanowires at different temperatures, the cross sections of the nanowire-embedded AAO templates were observed to determine the large-scale length uniformity. The length uniformity was determined by obtaining the average nanowire length from the nanowire growth front and dividing by the length of the template. Nanowires were sufficiently deposited with enough time so that the Cu overdeposits were fully exposed on the top surface of the template. Figure 3 shows the optical microscope images of the nanowire-embedded AAO templates with varying deposition temperature. It is clearly seen that the overall length uniformity of the Cu nanowires are significantly enhanced as the deposition temperature is decreased. At high deposition temperature condition, the growth front was shown to be very disordered and fluctuating while highly uniform growth front which is located near the top edge of the AAO template was observed at subzero centigrade temperature conditions. At 60.5°C, only about 65% of the total length of the template is filled while more than 95% of the nanowire length uniformity is achieved at -2.4°C. Considering that these samples are potentiostatically electrodeposited and the AAO template used in this work is extremely disordered, this result is remarkable. Note once again that Stacy and co-workers recently achieved about 93% of nanowire length uniformity by pulsed electrodeposition in a well-ordered homemade AAO template when the deposition temperature was between 1°C and 4°C [15].

Bottom Line: Even with highly disordered commercial porous anodic aluminum oxide template and conventional potentiostatic electrodeposition, length uniformity over 95% can be achieved when the deposition temperature is lowered down to -2.4°C.Decreased diffusion coefficient and ion concentration gradient due to the lowered deposition temperature effectively reduces ion diffusion rate, thereby favors uniform nanowire growth.Moreover, by varying the deposition temperature, we show that also the pore nucleation and the crystallinity can be controlled.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical Engineering, Yonsei University, Seoul, 120-749, Korea. hhcho@yonsei.ac.kr.

ABSTRACT
In this work, we report highly uniform growth of template-assisted electrodeposited copper nanowires on a large area by lowering the deposition temperature down to subzero centigrade. Even with highly disordered commercial porous anodic aluminum oxide template and conventional potentiostatic electrodeposition, length uniformity over 95% can be achieved when the deposition temperature is lowered down to -2.4°C. Decreased diffusion coefficient and ion concentration gradient due to the lowered deposition temperature effectively reduces ion diffusion rate, thereby favors uniform nanowire growth. Moreover, by varying the deposition temperature, we show that also the pore nucleation and the crystallinity can be controlled.

No MeSH data available.


Related in: MedlinePlus