TY - JOUR
T1 - Protection of Si photocathode using TiO2 deposited by high power impulse magnetron sputtering for H2 evolution in alkaline media
AU - Bae, Dowon
AU - Shayestehaminzadeh, Seyedmohammad
AU - Thorsteinsson, Einar B.
AU - Pedersen, Thomas
AU - Hansen, Ole
AU - Seger, Brian
AU - Vesborg, Peter Christian Kjærgaard
AU - Ólafsson, Sveinn
AU - Chorkendorff, Ib
PY - 2016
Y1 - 2016
N2 - Si is an excellent absorber material for use in photoelectrochemical
(PEC) hydrogen production. Only a few studies have been done using Si in
alkaline electrolyte for hydrogen evolution due to its poor chemical
stability in high pH electrolyte, indicating that a chemically stable
protection layer is essential. Here we investigate thin TiO2
films deposited by high power impulse magnetron sputtering (HiPIMS) as a
protection layer for a p-type silicon photocathode for
photoelectrochemical H2 evolution in a high pH electrolyte.
The X-ray reflectometry analysis reveals that the HiPIMS process
provides improved film density for TiO2 films (4.15 g/cm3), and consequently results in a significantly less corroded Si surface. The Si photocathode protected by the HiPIMS grown TiO2
film along with Pt as co-catalyst produced a photocurrent onset
potential of ~0.5 V vs. RHE in 1 M KOH and showed a 4% decay over 24 h
in KOH. In contrast, the sample with the TiO2 deposited using
conventional DC sputtering technique of similar thickness shows 20%
loss in photocurrent for the same time interval. Considering the fact
that the experiments were carried out not in the cleanroom, much less
corrosion loss can be obtained if done in dust-free condition. Hence,
these results suggest the HiPIMS technique as an improved approach for
the protection of photoelectrodes, which are unstable in alkaline
solution.
AB - Si is an excellent absorber material for use in photoelectrochemical
(PEC) hydrogen production. Only a few studies have been done using Si in
alkaline electrolyte for hydrogen evolution due to its poor chemical
stability in high pH electrolyte, indicating that a chemically stable
protection layer is essential. Here we investigate thin TiO2
films deposited by high power impulse magnetron sputtering (HiPIMS) as a
protection layer for a p-type silicon photocathode for
photoelectrochemical H2 evolution in a high pH electrolyte.
The X-ray reflectometry analysis reveals that the HiPIMS process
provides improved film density for TiO2 films (4.15 g/cm3), and consequently results in a significantly less corroded Si surface. The Si photocathode protected by the HiPIMS grown TiO2
film along with Pt as co-catalyst produced a photocurrent onset
potential of ~0.5 V vs. RHE in 1 M KOH and showed a 4% decay over 24 h
in KOH. In contrast, the sample with the TiO2 deposited using
conventional DC sputtering technique of similar thickness shows 20%
loss in photocurrent for the same time interval. Considering the fact
that the experiments were carried out not in the cleanroom, much less
corrosion loss can be obtained if done in dust-free condition. Hence,
these results suggest the HiPIMS technique as an improved approach for
the protection of photoelectrodes, which are unstable in alkaline
solution.
KW - Photocatalysis
KW - Titanium dioxide
KW - High power impulse magnetron sputtering
KW - Hydrogen evolution
U2 - 10.1016/j.solmat.2015.10.020
DO - 10.1016/j.solmat.2015.10.020
M3 - Journal article
VL - 144
SP - 758
EP - 765
JO - Solar Energy Materials & Solar Cells
JF - Solar Energy Materials & Solar Cells
SN - 0927-0248
ER -