A Self - Consistently Coupled Drift Diffusion and Monte Carlo Simulator to Model Silicon Heterojunction Solar Cells

Silicon heterojunction (SHJ) solar cell technology has continued to mature in recent years. A tremendous amount of research has been directed towards the optimization of the structure of the cell to obtain higher device performance. Any further improvement of the design requires a comprehensive understanding of all the factors that affect charge transport. Most theoretical attempts to describe charge transport have been based on traditional drift-diffusion (DD) methods, which are unable to capture the physics in crucial regions of the device. In this work we describe a method to self consistently couple a Monte Carlo (MC) solver to a DD solver. The MC solver is implemented to capture the high field behavior of the photogenerated carriers (holes) at the heterointerface. The selfconsistent coupling provides a quantitative link between device parameters (doping, thickness, defect densities, etc.) and device performance. This paper describes the first step in our effort to establish a full self-consistent multiscale solver that utilizes a DD (quasi-neutral regions), MC (high field regions) and kinetic Monte Carlo (defect transport) to rigorously study transport.