An all earth-abundant and precious metal-free photocathode based on a low-temperature fabricated amorphous silicon tandem junction is demonstrated to be an efficient device for solar water splitting. With a particular designed Al/Ni layer stack as photocathode/electrolyte contact an onset potential for cathodic photocurrent of 1.7V vs. RHE and a saturation photocurrent density of 7.2 mA/cm(2) were achieved. For a high-cost alternative with a Ag/Pt layer stack an even higher photocathode performance is demonstrated. Above all we present an approach for a dedicated photovoltaic and electrochemical development for solar water splitting. (C) 2015 Elsevier B.V. All rights reserved.