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

Abstract

Wide bandgap ferroelectric Pb(Zr0.20Ti0.80)O3 films were deposited on indium tin oxide (ITO) coated Si-pn+ substrates with an intention to form efficient Si-pn+/ITO/Pb(Zr,Ti)O3 (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 μA 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.

Nano‐Au and Ferroelectric Polarization Mediated Si/ITO/BiFeO3 Tandem Photocathode for Efficient H2 Production

“…On the other hand, the negative one will decrease J 0 and V op (See more clearly in Figure S6, Supporting Information). This point is just similar to those we found in Si/TTO/PZT photocathode, again indicating that E dp generated in ferroelectric film due to poling can drive the photogenerated electrons from Si junction to ferroelectric film, and then to the electrolyte. (2) If the BFO film is not positively poled, the role of Au NPs on improving the PEC performance is quite small.…”

“…Recently, we constructed an Si‐pn + /ITO/PZT tandem photocathode and found that the E dp generated in poled PZT film can drive the photogenerated electrons from Si‐pn + junction to PZT film, resulting in enhanced photoelectrochemical activity of the photocathode. A photocurrent of –1.2 mA cm –2 at 0 V versus RHE and an onset potential of 0.7 V versus RHE under 100 mW cm –2 Xe‐lamp illumination were obtained . Progress is made, however, the efficiency and onset potential is far from satisfactory.…”

Ferroelectric Materials: A Novel Pathway for Efficient Solar Water Splitting

“…Bi 2 FeCrO 6 (BFCO) exhibiting multiferroic properties plays a role as a photocathode with a narrow bandgap (1.9-2.1 eV), and an appropriate conduction band position, which shows a twofold increase of the photocurrent density after negative poling, as presented in Figure 8 [105]. Recently, Shen et al performed many studies on Pb(Zr,Ti)O 3 (PZT) and revealed that ferroelectric PZT films deposited on indium tin oxide (ITO)-coated quartz glass [106,107] along with PZT films decorated with Ag nanoparticles on an ITO coated Si-pn + junction [108] can function as stable and effective photocathodes for water splitting. More importantly, polarization switching can drive the photogenerated electrons transfer process, which then results in significantly enhanced PEC activity.…”

Plasmonic enhanced Cu2O-Au-BFO photocathodes for solar hydrogen production

“…Heterostructure photoelectrodes, which are comprised of two different semiconductors in stacked layers, have been shown to improve the separation of photo-generated carriers, with the internal electric field in the heterojunction region promoting carrier separation. In a heterostructure, an incremental V op is usually achieved, but the photocurrent is normally limited by the blocked transfer of photo-generated carriers at the interface 6 . The key issue associated with heterostructure photoelectrodes is the energy band edge alignment of the two semiconductor layers.…”