Front side degradation of silicon solar cells by rear side laser processing

We show an impact of rear side laser processing on the front surface recombination of thin silicon solar cells. The front surface recombination velocity of 45 µm thick back-contact back-junction monocrystalline silicon solar cells increases from 500 cm s -1 to 12000 cm s 1 by a rear side laser contact separation process. This increased recombination decreases the energy conversion efficiency from 18.8 % to 7.5 %. The internal quantum efficiency at short wavelength of 600 nm is also decreased from 0.88 to 0.33 confirming the increased front surface recombination by rear side laser processing.