Laser Annealing to Enhance Performance of All-Laser-Based Silicon Back Contact Solar Cells

This study investigated the use of lasers for the fabrication of interdigitated back contact (IBC) solar cells where low-power laser annealing was used to improve the device performance. We have successfully demonstrated a novel concept of low-power laser annealing after the high-power laser doping which can effectively activate the dopants and increase the diffusion length as noticed by the decrease of sheet resistance. The low-power laser annealing decreased the series resistance and increased the fill factor to 77.2%, compared to 68.1% in nonannealed devices. The photovoltaic efficiency of 18.9% was achieved in laser annealed cells, compared to 16.5% in nonannealed cells.