3D simulations of organic solar cells

Drift-diffusion (DD) and Kinetic Monte Carlo (KMC) simulations are commonly used methods for understanding the physics of organic photovoltaic devices. While DD methods have been successfully employed to model and explain device characteristics, KMC simulations open up the possibility to investigate the fundamental processes involved in the operation of solar cells. In this chapter, we give a description of two- and three-dimensional (2D and 3D) DD and KMC simulations. Going beyond one-dimensional simulation techniques allows for a better description of device operation and for a deeper understanding of more fundamental processes. After briefly introducing the basic processes involved in the operation of organic photovoltaic devices, we present an overview of DD and KMC techniques, including some of the technical challenges in the implementation of 2D and 3D simulations. Finally, we compare some results of DD and KMC simulations; in doing so, we particularly focus on the use of 2D and 3D simulations to clarify the impact of the active layer morphology on device efficiency.