Application of laser technique for fabrication of rear dot-contact of PERC crystalline silicon solar cell

One of the factors restricting the appliance of high-efficiency passivated emitter and rear cell(PERC)-type solar cell to the industrial silicon solar cell is that the formation of good ohmic contacts on the rear side of PERC-type solar cell passivated by Al₂O₃ film. This work focuses on the formation of rear local contacts instead of high efficiency by using laser ablation with 532 nm wavelength and conventional photolithographic technique. The results of the contact formed by these two methods are compared and analyzed. In addition, we compare and analyze the rear local contacts formed by laser ablation and laser firing using 532 nm line laser. The results suggest that the laser ablation can provide better contacts in the PERC-type solar cell. The contact resistance of the solar cell using laser ablation technique is reduced to 1.24 Ω·cm² from 10.7 Ω·cm² using laser firing method, and the efficiency is enhanced from 4.2% to 10.7%.