Laser processing of A!_2G_3/a-SiC_x:H stacks: a feasible solution for the rear surface of high-efficiency p-type c-Si solar cells

摘要

We explore the potential of laser processing aluminium oxide (Al_2O_3)/amorphous silicon carbide (a-SiC_x:H) stacks to be used at the rear surface of p-type crystalline silicon (c-Si) solar cells. For this stack, excellent quality surface passivation is measured with effective surface recombination velocities as low as 2 cm/s. By means of an infrared laser, the dielectric film is locally opened. Simultaneously, part of the aluminium in the A1_2O_3 film is introduced into the c-Si, creating p+ regions that allow ohmic contacts with low-surface recombination velocities. At optimum pitch, high-efficiency solar cells are achievable for substrates of 0.5-2.5 Ω, cm.