Self-aligned nanoforest in silicon nanowire for sensitive conductance modulation.
A self-aligned and localized nanoforest structure is constructed in a top-down fabricated silicon nanowire (SiNW). The surface-to-volume ratio (SVR) of the SiNW is enhanced due to the local nanoforest formation. The conductance modulation property of the SiNWs, which is an important characteristic in sensor and charge transfer based applications, can be largely enhanced. For the selective modification of the channel region, localized Joule-heating and subsequent metal-assisted chemical etching (mac-etch) are employed. The nanoforest is formed only in the channel region without misalignment due to the self-aligned process of Joule-heating. The modified SiNW is applied to a porphyrin-silicon hybrid device to verify the enhanced conductance modulation. The charge transfer efficiency between the porphyrin and the SiNW, which is caused by external optical excitation, is clearly increased compared to the initial SiNW. The effect of the local nanoforest formation is enhanced when longer etching times and larger widths are used.
Department of Electrical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, Republic of Korea.
Myeong-Lok
ML
Seol
Jae-Hyuk
JH
Ahn
Ji-Min
JM
Choi
Sung-Jin
SJ
Choi
Yang-Kyu
YK
Choi
D015374:Biosensing Techniques; D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods; D053768:Metal Nanoparticles / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D055095:Optics and Photonics; D011166:Porphyrins / Q000737:chemistry; D012666:Semiconductors; D012825:Silicon / Q000737:chemistry; D013997:Time Factors
D011166:Porphyrins; D012825:Silicon