Laser-fired rear contacts for crystalline silicon solar cells

From today's viewpoint future solar cells will be thinner, of higher efficiency and produced in greater numbers. A solar cell concept able to fit these developments could be the passivated emitter and rear cell. With a new laser-based process (laser-fired contacts), the rear point contact pattern of this concept can be implemented industrially. After the deposition of a dielectric passivation layer and a metal layer on top, a Nd-YAG laser is used to alloy the contact points through the dielectric layer. Excellent efficiencies have been achieved which approach closely those of reference cells processed by photolithography. This demonstrates the high potential of the new laser-based technique