Theoretical study of role of Ag film thickness on surface plasmon resonance in P3HT: PCBM/Ag film

Abstract

Surface Plasmon resonance (SPR) technique is used to characterize the thickness of nanometer range metallic films. The poly (3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) is used as the most efficient solar cell. In this paper, we have theoretically studied the variation of reflectance of medium with the thickness of Ag film on P3HT-PCBM: Ag composite film, which is deposited on prism surface. He-Ne laser at exciting wavelength of 632.8 nm is used for theoretical investigation for SPR study. The reflectance of P3HT-PCBM: Ag film becomes zero at 51 nm thickness of nano silver film and 23 nm thickness of P3HT-PCBM film. The result shows strong dependence of reflectance on thickness of P3HT-PCBM: Ag film. Surface Plasmon resonance in nanostructure silver film is responsible for this unusual effect.