First pin/pin micromorph modules by laser patterning

The well-established laser-scribing currently used for a-Si:H module fabrication, has been applied to “micromorph” (a-Si:H/μc-Si:H) tandem solar cells deposited on glass/ZnO substrates. Thereby, a laser at a wavelength of 1064 nm was used for scribing the ZnO and a laser with a wavelength of 532 nm for the silicon film scribing. It is shown that with glass-side scribing, both the 0.3 μm thick a-Si:H top cell as well the 3 μm μc-Si:H bottom cell can be patterned in one single pulse. Monolithic integrated series connection is obtained with a total of 3 patterning steps. These first experiments allowed for fabrication of micromorph mini-modules (area 23.3 cm²) having 6 segments has been fabricated with a stable aperture efficiency of 9.1% (V_∝=8.014 V, FF=66.6%, I_sc=39.72 mA)