Laser Sintering of Screen-printed Silver Paste for Silicon Solar Cells

This paper proposes laser sintering of screen-printed silver grids, which is compatible with low temperature surface passivation materials such as intrinsic hydrogenated amorphous silicon and has the potential of fabricating high efficiency solar cells at a low cost. It was found that a nanosecond pulsed laser (lambda = 532 nm) can locally and controllably fire silver paste through SiNx without punching through the underneath phosphorus-diffused emitter. A low temperature belt firing prior to laser sintering is helpful for improving the quality of laser sintering. Laser sintered cells reached 17.3% cell efficiency on 239 cm(2) cell area.