Optical geometries for fiber-based organic photovoltaics

Poly(3-hexylthiophene):1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 photovoltaic devices were fabricated as a cladding onto large diameter optical fibers. The performance of the devices was dependent on fiber diameter as well as the angle of incidence of light onto the cleaved fiber face. The authors suggest that absorption by the active layer is dominated by different mechanisms at different angles: evanescent coupling of the light at small incident angles and far field scattering of the light from the fiber at higher angles. Further, a comparison of devices that only partially clad the fiber to those that fully clad suggests the formation of confined radiation modes.