Optimization of Laser-opening Pattern for the Efficiency Improvement of Industrial PERC Solar Cell

In this paper, we proposed and demonstrated the application of a rear busbar-parallel line opening pattern (BLOP) to reduce the series resistance and improve the PERC type cell efficiency. The proposed cells with BLOP gave an average efficiency of 21.40%, series resistance of 0.631 $\omega $ -cm$^{\mathbf {2}}$ and fill factor of 80.1 % while the reference cells gave an average efficiency of 21.34%, series resistance of 0.646 $\Omega $ -cm$^{\mathbf {2}}$, and fill factor of 79.9 %. This BLOP method increases the cell efficiency and fill factor by providing a better path way for holes underneath the rear busbar to be collected at the rear contact. As the employment of BLOP does not affect the capacity of the mass production, it is a very practical and readily available way to improve the performance of PERC type cells in mass production.