Proceedings Article | 4 September 2009
KEYWORDS: Gold, Solar cells, Nanoparticles, Absorption, Glasses, Quantum efficiency, Surface plasmons, Organic photovoltaics, Metals, Resonance enhancement
The surface Plasmon resonance, which occurs between the dielectric material layer and the metal surface, is of great
interest in several fields including the materials to fabricate solar cell, because the enhanced electromagnetic field caused
by surface Plasmon resonance increases the optical absorption of solar cell by adding metal nanoparticles.[1] The metal
nanoparticles used in this paper are spherical gold nanoparticles, which deposit on the surface of device, can enhance the
optical absorption via the excitation of surface Plasmon resonance in an organic photovoltaic cell. [2] The shape, size,
spacing, and the surrounding dielectric materials of nanoparticles affect the absorption ratio and absorption peak with
different wavelengths.[3-4] The gold nanoparticles used in this paper are 5nm, 10nm, and 20nm in diameter, which are
deposited on ITO (indium tin oxide) glass substrates, and then another two organic materials deposit on it. The first
organic materials are Poly (styrenesulfonate) /
poly(2,3-dihydro-thieno-1,4-dioxin) (PEDOT) and poly
{2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene} (MEHPPV) with Fullerene(C60) mixtures, the second materials are
poly(3-hexylthiophene)(P3HT) and [6,6]-phenyl-C71 butyric acid methyl ester(PC70BM) mixture, and the third materials are
poly(3-hexylthiophene)(P3HT) and [6,6]-phenyl-C61 butyric acid methyl ester(PCBM) mixture act as p-type and n-type
organic semiconductor. By using the DDSCAT software, The Discrete Dipole Approximation for Scattering and
Absorption of Light by Irregular Particles, the SPR enhancement and absorption peak can be predicted in this software,
and the enhancement caused by surface Plasmon resonance within the layers of this device is supposed to be related to
the photocurrent in this organic photovoltaic cell with gold nanoparticles. Under halogen illumination, the proposed
enhancement is around 20~30% power efficiency in this device agrees well to the result as DDSCAT software simulated.