Abstract
High-efficiency technology to the photodiodes has become a critical issue. Surface plasmon resonance (SPR) would be one of the means for solving the problem. Photocurrent of photodiodes is enhanced by metal nanoparticles, which induce the localized SPR, deposited on light-receiving surface of the photodiodes. Most previous studies had been focused on the photocurrent enhancement effect around maximum absorption wavelength of the nanoparticles. The effect except the wavelength has not been paid attention yet. For instance, in case of a solar cell, metal nanoparticles which have maximum absorption wavelength at around 500nm, have been widely employed since solar light has higher illuminance around 500nm. However, the photocurrent enhancement effect of the nanoparticles has not studied around near-infrared light though illuminance of the near-infrared light is quite valuable. Therefore, in this study, experimental investigation of photocurrent enhancement effect was conducted using Au nanoparticles with 100 and 150nm in nominal diameters, which have maximum absorption wavelengths at around 500nm. As a result, the photocurrent enhancement effect was obtained at near-infrared wavelengths. In addition, higher enhancement effect was achieved when the two Au nanoparticles were mixed. This would be ascribable to obtaining wider bandwidth of maximum absorption wavelengths due to mixing of different-size nanoparticles.
