Optimization of ultraviolet laser doping for crystalline silicon solar cells with a novel segmented selective emitter design

This paper reports on the use of ultraviolet laser for forming segmented selective emitters on POCl 3 n +pp + solar cells. Laser scan speed, pulse power, and repetition rate are optimized to minimize laser-induced defects, which are found to enhance recombination and reduce the local open-circuit voltage. Laser-doped selective emitters formed by locally driving in additional phosphorous from the diffusion glass are well suited for an etchback process without the need for a mask. In this paper, we show a novel selective emitter design that is segmented instead of continuous, combined with an emitter etchback process gives an efficiency improvement of about 0.3% absolute over a standard industrial type solar cell and 0.2% absolute improvement over a non-segmented selective emitter solar cell. Copyright (c) 2012 John Wiley & Sons, Ltd.