Metamaterial perfect absorber solar cell (Conference Presentation)

Abstract

We propose a metamaterial perfect absorber (MPA) solar cell to utilize the light confinement effect of MPA and to enhance the light absorption of the cell. The MPA consists of two distinct metallic structures sandwiching a thin dielectric layer as a spacer. Under light irradiation, a magnetic resonance mode is excited in the MPA at a certain wavelength, leading to light confinement in the dielectric thin layer. We propose to replace the dielectric layer with the photoelectric conversion layer of an organic thin-film solar cell (OSC), so as to confine the light into the layer, leading to light absorption enhancement without changing the layer thickness. In this research, we introduced metallic nanostructures into a solar cell device to form the metamaterial perfect absorber configuration, and examined the light absorption enhancement of the cell. A periodic Ag nanostripe array was fabricated on a transparent electrode. Thin films of zinc oxide, poly (3-hexylthiophene): [6, 6]-phenyl-C61-butyric acid methyl ester (P3HT:PC61BM), molybdenum oxide, and aluminum were laminated on the Ag nanostripes so as to make a solar cell. Reflection spectra were measured with light incident from the glass side of the MPA solar cell. The relative extinction is the ratio of the extinction spectra of OSCs with and without Ag nanostripes were calculated. The average extinction ratio in the absorption wavelength range of the P3HT:PC61BM layer was 1.18, suggesting the MPA configuration confined sunlight into the P3HT:PC61BM layer, leading the light absorption increase of the layer by a factor of 18%.