Plasmonic nanoparticle arrays fabricated and modified by energetic ions for chemical sensors

エネルギーイオンによる化学センサーのためのプラズモニックナノ粒子集合体の製作と改質

2014-03-25

2014-03-25

Plasmonic nanoparticles made of silver and gold exhibit unique optical properties due to localized surface plasmon resonance in the visible wavelength range. A plasmonic sensor is one of the most useful applications of such nanoparticles. In this thesis, energetic ion processes including ion implantation, sputtering and plasma cleaning were utilized to fabricate and modify silver or gold nanoparticle arrays for chemical sensing applications. The early chapter of this thesis describes the method to fabricate well-ordered and densely arranged silver nanoparticles buried in a thermally grown SiO2 by implanting with 350 keV silver ions. Cross-sectional transmission electron microscopy and scanning transmission electron microscopy revealed the presence of a two-dimensional array of silver nanoparticles of 25−40 nm in diameter located at a depth of ~130 nm, together with the self-organization of -layer of tiny silver nanoparticles aligned along the SiO2/Si interface. Next, a sputter deposition technique to prepare densely arranged silver nanoparticle which posses a nice plasmonic characteristic was presented and then plasma exposure was applied for cleaning the nanoparticle arrays. Plasma treatments of silver nanoparticles were found to bring about blue-shift and narrowing in their localized surface plasmon resonance. The author found that the plasmonic properties of gold nanoparticles were also altered by energetic ion irradiation and plasma exposure. Finally, the plasmonic sensing ability of gold nanoparticle for dilute cyclohexane was examined. Gold nanoparticle arrays were fabricated on SiO2 by a sputter deposition technique. The change in an extinction spectrum of gold nanoparticle arrays before and after exposure of cyclohexane vapor enabled to detect it. The gold nanoparticle array prepared by heating at 300 °C was densely arranged on the substrate and exhibited the highest sensitivity for cyclohexane. The experimentally detectable concentration of cyclohexane was as low as 0.5 vol%, much lower than its explosion limit.

博士（工学）

京都工芸繊維大学

14303甲第690号

http://hdl.handle.net/10212/2158

en

ETD

Thesis or Dissertation

Thesis