Outstanding Surface Passivation for Highly Efficient Silicon Solar Cells Enabled by Innovative Al _<i>y</i> TiO _<i>x</i> /TiO _<i>x</i> Electron?Selective Contact Stack

Passivating contacts based on transition metal oxides (TMOs) have the potential to overcome existing performance limitations in high-efficiency crystalline silicon (c-Si) solar cells, which is a significant driver for continuing cost/Watt reductions of photovoltaic electricity. Herein, innovative stacks Al-alloyed TiO x (Al y ) and pure as transparent electron-selective passivating n-type c-Si surfaces are explored. An optimized stack 2 nm Al shown provide both record-quality surface passivation excellent electrical contact, with recombination current density prefactor J 0 2.4 fA cm?2 specific contact resistivity ? c 15.2 m? cm2. The this significantly exceeds previously reported values or doped single layers, SiO /TiO stacks, a-Si:H/TiO other technologies. Furthermore, an efficiency 21.9% attained by incorporating full-area rear cell. findings set new benchmark oxide-based contacts, bringing it level par state-of-the-art /poly-Si while greatly improving optical transparency.