Bifacial PERC Solar Cell Designs: Bulk and Rear Properties and Illumination Condition

We report on the evaluation of cell performances of the bifacial passivated emitter and rear cell (PERC) structures for both p- and n-type Cz-Si. We compared four conditions: Front-side illumination, with and without the rear metal contact, rear-side illumination, and double-side illumination. Furthermore, the effects of the rear contact area and the rear passivation surface recombination velocity (SRV) were evaluated. The numerical simulations were based on the experimental results of the p-type bifacial PERC performance, and we attempted to determine optimized cell designs for each condition. The results showed that the rear passivation SRV determined the bulk condition: An n-type bulk resistivity of 1 $\Omega$-cm and p-type bulk resistivity with BO-cluster deactivation of 0.5 $\Omega$-cm were suitable for a smaller and larger SRV, respectively.