Origins of performance in fiber-based organic photovoltaics

Using ray tracing and optical path iteration, we present a mathematical model for light transmission, absorption, and loss in fiber-based organic photovoltaics. Simulations based on this model give an optimum incident angle, position, and an optimum aspect ratio in terms of other parameters of the fiber photocell. Further, the predicted relationship between current generation and incident angle correlates well with experimental data for a given fiber length. Finally, we show that experimental results on current generation versus fiber diameter are well reproduced by our simulation for fiber diameters of the order of the wavelength of incident light.