AVS 57th International Symposium & Exhibition
    Advanced Surface Engineering Tuesday Sessions
       Session SE-TuP

Paper SE-TuP3
Spatially Controlled Heat Generation by Local Plasmon Resonator

Tuesday, October 19, 2010, 6:00 pm, Room Southwest Exhibit Hall

Session: Advanced Surface Engineering Poster Session
Presenter: K. Namura, Kyoto University, Japan
Authors: K. Namura, Kyoto University, Japan
M. Suzuki, Kyoto University, Japan
R. Tabuchi, Kyoto University, Japan
K. Nakajima, Kyoto University, Japan
K. Kimura, Kyoto University, Japan
Correspondent: Click to Email
Heat generation from noble metal nanoparticles due to their local plasma resonance is attracting much attention because of the fast response and the flexibility to choose heating area. The conventional nanoparticle heaters are fabricated by simple lithography of Au thin films on glass or Si substrate so that they absorb only a few 10 % of the incident light even at the wavelength of the local plasma resonance. Therefore, they are ineffective from the viewpoints of not only the fabrication cost but also photothermal conversion. In addition, it is difficult to spatially control the generated heat because photothermal conversion efficiency is constant for all nanoparticles.

Recently, we demonstrated the self-assembling of Au nanoparticles/ dielectric layer/ Ag mirror sandwiches, namely, the local plasmon resonator, by using a dynamic oblique deposition technique1. Due to strong interference, their optical absorption can be controlled between 0.1% and 100% by changing the thickness of the dielectric layer. Although we focused our attention only on the local field enhancement in that work, now we notice that photothermal conversion efficiency can be spatially tuned by using the local plasmon resonators. This work is the feasibility study of application of the local plasmon resonator to the spatially controlled nanoheaters.

We prepared combinatorial local plasmon resonator chips which have different thicknesses of Au and the dielectric layers on a single substrate of 50×50 mm2 by oblique deposition and measured the absorption spectrum on each element. In order to evaluate the heat generation from Au nanoparticles, we measured the temperature of the water, with which a small cell created on a local plasmon resonator was filled, irradiating the laser of the wavelength of 785 nm. The temperature of the water on the element with high absorption becomes higher than that on the element with low absorption. The change in temperature proportional to absorption of the element in the local plasmons resonator chips. This suggests that the photothermal conversion efficiency can be controlled by the interference. Consequently, local plasmon resonator can be applied to the nanoheaters, which can spatially control the heat generation.

This work was supported by KAKENHI 21656058 and by the Iketani Science Foundation.

1. M. Suzuki, et al., Journal of Nanophotonics, 3, 031502 (2009).