Mask-less fabrication of a-Si solar cell using laser scribe process

The new practical integration process of amorphous silicon (a-Si) solar cells using laser scribing lithography is presented. A 12-stage series-connected, integrated solar cell having a structure of glass-TCO/PIN/metal electrode was fabricated by two laser scribing steps and one metal masking step, or three laser scribing steps alone. The former cell has 6.4% conversion efficiency under AM1 (100mW/cm/sup 2/) and 7.15% under 500Lx fluorescent lamp (69% effective area on 10cm x 10cm substrate), and the latter has 4.11% conversion efficiency under AM1 (83% effective area on 10cm x 10cm substrate). The scribe process is carried out with YAG laser scriber using Q-switched 1.06 micron wavelength light.