다공성실리콘내 Fe3O4나노입자의 압력침착과 채움밀도 모니터링 방법

Abstract

In this paper, we propose a new method to infiltrate Fe3O4-nanoparticles into a porous silicon film and a monitoring tech- nique to detect packing density of nanoparticles within the film. Recently, research to use porous silicon as a drug carrier or a new functional sensor material by infiltrating Fe3O4-nanoparticles has been extensively performed. However, it is still necessary to enhance the packing density and to develop a monitoring technique to detect the packing density in real time. In this light, we forcibly injected a nanoparticle solution into a rugate-structured free-standing porous silicon (FPS) film by applying a pressure difference between the two sides of the film. We found that the packing density by the pressure-infil- tration method proposed in this paper is enhanced, relative to that by the previous diffusion method. Moreover, a continuous shift in wavelength of the rugate reflectance peak measured from the film surface was observed while the nanoparticle solu- tion was being injected. By exploiting this phenomenon, we could qualitatively monitor the packing density of Fe3O4-nano- particles within the FPS film with the injection volume of the nanoparticle solution.