Scalable Techniques for Producing Field-Effect Passivation in High-Efficiency Silicon Solar Cells

This paper presents techniques to tailor and optimize the field-effect passivation of silicon surfaces using the deposition and field-assisted migration of potassium ions. While field-effect passivation of this nature has previously been demonstrated using laboratory scale techniques, in this paper, it is shown how it can be realized using fast and scalable ion deposition and migration methods. Together, the deposition and migration processes are seen to produce excellent improvements to the surface passivation of oxidized 1-Ω·cm n-type float-zone silicon. Effective lifetimes as high as 2.1 ms are observed, in the best case yielding a surface recombination velocity as low as 3.3 cm/s with a corresponding surface dark saturation current density of 8.4 fA/cm
²
.