Characterization of MIS Photoanode with a Thin SiO2 Layer for Photoelectrochemical Water Splitting

The results of capacitive and current voltage measurements on metal-insulator-semiconductor (MIS) photoanode structures with n-type silicon substrate are presented in this paper. The best photo-voltage and photo-current results were obtained on MIS structures with SiO2 grown by Atomic Layer Deposition (ALD). High ideality factor observed in the voltage range 0.1-0.3 V indicates the tunnelling as a dominant transport mechanism through the ALD grown SiO2 layer. Low Flat band voltages confirmed good passivation properties of the prepared ALD grown SiO2. High saturation current and low overpotential of MIS photo-electrochemical structure with ALD SiO2 and RuO2 catalytic layer predict good applicability of ALD prepared passivation layer for light assisted water splitting.