[1Da01-09] Surface Science(SS1) Physical Property

[1Da08] Infrared absorption enhancement on silicon surface with line and space nanostructures

*Toru Shimada¹, Shiori Sato¹, Yushi Suzuki², Nobutaka Shioya³, Takafumi Shimoaka^3,4, Takeshi Hasegawa³ (1. Department of Science, Faculty of Education, Hirosaki University, 2. Graduate School of Science and Technology, Hirosaki University, 3. Institute for Chemical Research, Kyoto University, 4. Graduate School of Science and Technology, Gunma University)

Molecules show strong infrared absorption when adsorbed on metal nanoparticles or on the surface of discontinuous metal thin films. It is known as surface-enhanced infrared absorption (SEIRA). We conducted SEIRA measurements on line and space nanostructured surfaces of silicon, a semiconductor material. The enhancement factors of infrared absorption for the line and space nanostructures were found to be three to four. Comparing the enhancement factors for the peaks at lower and higher wavenumbers, the peak at lower wavelength was more enhanced. Furthermore, longer line periods give a greater enhancement factor at the same wavelength. However, when the line period is more than about one-tenth of the excitation wavelength, the enhancement effect is smaller.