Virtual prototyping and optimization of novel solar cell designs

Abstract

Nano-scale structures have been proposed as a low cost mechanism to enhance solar cell efficiency. Computer simulations can be used to rapidly and cheaply prototype and optimize these novel designs, however the simulations are challenging due to the geometric complexity, the highly dispersive materials, and the necessity of performing broadband simulations over the solar spectrum. We show how the finite-difference time-domain (FDTD) method in conjunction with particle swarm optimization (PSO) can be used to efficiently optimize these designs. We apply the method to two specific examples: thin film silicon plasmonic solar cells and photonic crystal organic solar cells. In each case, optical enhancements of approximately 15% can be achieved. The optimization requires a few hundred simulations which can be achieved in a few hours on a good workstation. Finally, we consider the steps necessary to perform combined optical and electrical simulations to fully characterize these devices.