Lifetime and efficiency limits of crystalline silicon solar cells

A new parameterization for Auger recombination in silicon has been determined, which accurately fits the highest available experimental lifetime data for arbitrary injection level and dopant density, for both n-type and p-type dopants. Our analysis confirms that Auger recombination is enhanced above the traditional free-particle rate at both low injection and high injection conditions. The new parameterization is used to show that Coulomb-enhanced Auger recombination imposes the most severe bound on the achievable efficiency of crystalline silicon solar cells, with a maximum limiting efficiency of 29.05% determined for a high resistivity silicon base (90μm thick). The limiting efficiency reduces for more heavily doped silicon and is lower for n-type silicon compared to p-type silicon.