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 ⁺ –p–p ⁺ 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 © 2012 John Wiley & Sons, Ltd.