Enhanced photocathodic behaviors of Pb(Zr0.20Ti0.80)O3 films on Si substrates for hydrogen production

Wide bandgap ferroelectric Pb(Zr0.20Ti0.80)O-3 films were deposited on indium tin oxide (ITO) coated Si-pn(+) substrates with an intention to form efficient Si-pn(+)/ITO/Pb(Zr,Ti)O-3 (PZT) photocathode for hydrogen production. Depolarization electric field generated in PZT film due to poling can drive the photogenerated electrons from Si-pn(+) junction to PZT film, resulting in enhanced photoelectrochemical activity of the photocathode. Comparing the electrode with as-prepared PZT film, the photocurrent increased from -100 mu A cm(-2) to -1.2 mA cm(-2) at 0 V vs. reversible hydrogen electrode (RHE) and the onset potential from 0.36 V to 0.7 V vs. RHE under 100 mW cm(-2) illumination, manifesting the great advantage of depolarization electric field in driving the photogenerated carriers not only in the ferroelectric film but also on the interface of different semiconductors. (C) 2015 AIP Publishing LLC.