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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.


SEM images of backside of the AAO templates with Au/Cr seed layers partially etched away. Dark areas indicate empty pores. (a) -1.5°C; (b) 60.5°C.
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Figure 4: SEM images of backside of the AAO templates with Au/Cr seed layers partially etched away. Dark areas indicate empty pores. (a) -1.5°C; (b) 60.5°C.

Mentions: To determine the pore nucleation, the back side of the nanowire-embedded AAO templates with Au/Cr layer partially etched away were observed using SEM which is presented in Figure 4. It can be clearly seen that at 60.5°C empty pores were easily observed whereas over 90% of the pores were nucleated at -1.5°C. Obviously, this is attributed to the different growth process of the Cu nanowires at various deposition temperatures. At high deposition temperature, the initial nucleation process is mainly instantaneous where the nuclei are mainly formed in the initial voltage pulse [30]. However, by lowering the deposition temperature, the initial nucleation process tends to shift toward progressive nucleation mode in which the nuclei are continuously formed during the nanowire growth. This can be verified by analyzing the current maxima at the initial stage of the electrodeposition curve in Figure 2b where two different nucleation modes are presented along with experimental data in a normalized form [31]. When progressively nucleating, the chances of pore nucleation during the nanowire growth are higher than instantaneous nucleation since the nuclei are continuously formed during the nanowire growth, even after the initial stage. Moreover, as mentioned earlier, slow nanowire growth also favors more pores to be nucleated before the pores are blocked. Therefore, by lowering the deposition temperature, a large-scale length uniformity and pore filling can be simultaneously achieved.


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)

SEM images of backside of the AAO templates with Au/Cr seed layers partially etched away. Dark areas indicate empty pores. (a) -1.5°C; (b) 60.5°C.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 4: SEM images of backside of the AAO templates with Au/Cr seed layers partially etched away. Dark areas indicate empty pores. (a) -1.5°C; (b) 60.5°C.
Mentions: To determine the pore nucleation, the back side of the nanowire-embedded AAO templates with Au/Cr layer partially etched away were observed using SEM which is presented in Figure 4. It can be clearly seen that at 60.5°C empty pores were easily observed whereas over 90% of the pores were nucleated at -1.5°C. Obviously, this is attributed to the different growth process of the Cu nanowires at various deposition temperatures. At high deposition temperature, the initial nucleation process is mainly instantaneous where the nuclei are mainly formed in the initial voltage pulse [30]. However, by lowering the deposition temperature, the initial nucleation process tends to shift toward progressive nucleation mode in which the nuclei are continuously formed during the nanowire growth. This can be verified by analyzing the current maxima at the initial stage of the electrodeposition curve in Figure 2b where two different nucleation modes are presented along with experimental data in a normalized form [31]. When progressively nucleating, the chances of pore nucleation during the nanowire growth are higher than instantaneous nucleation since the nuclei are continuously formed during the nanowire growth, even after the initial stage. Moreover, as mentioned earlier, slow nanowire growth also favors more pores to be nucleated before the pores are blocked. Therefore, by lowering the deposition temperature, a large-scale length uniformity and pore filling can be simultaneously achieved.

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.