Laser Chemical Processing of n-Type Emitters for Solid-Phase Crystallized Polysilicon Thin-Film Solar Cells

We report on the application of laser chemical processing (LCP) to fabricate n-type emitters for polysilicon thin-film solar cells on glass. Sheet resistance values of 2-5 kΩ/□ with a peak phosphorus doping concentration in the range 8 × 10¹⁸ -1 × 10¹⁹ cm^-3 at a shallow doping depth of less than 350 nm are achieved. After dopant activation and a hydrogenation process, the best cell has an average V_oc of (446 ± 7) mV and a pseudofill factor (pFF) of (68.3 ± 0.9)%. This paper demonstrates that LCP can be successfully applied to fabricate an active layer for polysilicon thin-film solar cells on glass. Further improvement in the V_oc and the pFF may be possible by optimizing the post-LCP annealing and hydrogenation process, as well as using a poly-Si film of superior material quality.