Dual-purpose tunnel oxide passivated contact on silicon photoelectrodes with high photovoltages for tandem photoelectrochemical devices enabling unassisted water splitting

Tunnel-oxide-passivated contact on a crystalline Si improves the photovoltage of Si photoelectrode to reach 640–650 mV even after a high-temperature process up to 600 °C, which makes it useful as the bottom cell of a monolithic tandem device.