High-efficiency CVD multi-layer thin-film silicon solar cells

We present new results for high-efficiency multilayer thin-film silicon solar cells deposited by CVD (chemical vapour deposition) onto electrically inactive p⁺⁺-type CZ silicon substrates. The cell isolation and the substrate thinning applied to the cells can enhance the short-circuit current density, open-circuit voltage, the fill-factor, and hence achieve higher energy-conversion efficiency. For n-p-n-p-n active layers of a total thickness of 17-μm combined with a 15-μm-thick p⁺-type buffer layer, the resulting CVD multi-layer thin-film silicon solar cells exhibit a V_oc of 664.2 mV, a J_sc of 32.9 mA/cm², a FF of 82.5%, and an energy-conversion efficiency of 17.6%, as measured by Sandia National Laboratories, which is the highest efficiency ever reported for thin-film silicon solar cells deposited onto an inert substrate