Study of exciton diffusion in carbon-nanotube thin-films*

Carbon nanotubes have attracted considerable attention for their potential use in organic thin-film photovoltaic devices. Given the fact that the exciton-transfer properties are directly related to improving the efficiency of these devices, it is crucial to develop a model of exciton diffusion in various carbon nanotube composites and study the diffusion mechanism. Here, we focus on the role of different properties of carbon nanotubes, including chirality and spacing, on exciton diffusion. We generate realistic nanotube meshes with different properties through which the motion of excitons is tracked using a Monte Carlo simulation. Finally, we compare the calculated exciton diffusion rate and diffusion length to experiment and develop an understanding of how different conditions of carbon nanotube aggregation affect diffusion properties.