Analysis of the recombination mechanisms in silicon solar cells with the record 26.6% photoconversion efficiency

The performance of high-efficiency textured silicon solar cells is modelled within the thin-base approximation. In addition to the standard recombination mechanisms (Shockley-Read-Hall, radiative, and Auger), our approach includes the trap-assisted exciton Auger recombination and the space charge region recombination. A simple phenomenological expression is used for the photocurrent external quantum efficiency in the long-wavelength part of the absorption spectrum. The key parameters of textured silicon solar cells, such as short-circuit current, open-circuit voltage and photoconversion efficiency, are determined theoretically. They are in good agreement with the experimental results obtained for the heterojunction solar cells with the record efficiency of 26.6% produced by Yoshikawa et al. (2017). The theoretical optimal doping level and base thickness of these solar cells are found to be quite close to the experimental ones.