Enhanced Hydrogen Evolution under Simulated Sunlight from Neutral Electrolytes on (ZnSe) (CuIn Ga Se ) Photocathodes Prepared by a Bilayer Method.

A (ZnSe) (CuIn Ga Se ) photocathode with a bilayer structure was fabricated and found to exhibit a photocurrent almost twice that of a photocathode with a monolayer structure during hydrogen evolution from water. The cathodic photocurrent reached maximum values of 12 and 4.9 mA cm at 0 and 0.6 V in a neutral phosphate buffer under simulated sunlight, while the half-cell solar-to-hydrogen conversion efficiency was 3.0 % at 0.6 V , with a maximum value of 3.6 % at 0.45 V . Cross-sectional mapping of the electron-beam-induced current established that the increased photocurrent can be attributed to improved uniformity at the solid-liquid junction in the bilayer sample, which results in enhanced carrier collection.