TY - JOUR
T1 - Electrochemistry of sputtered hematite photoanodes
T2 - a comparison of metallic DC versus reactive RF sputtering
AU - Sinha, Rochan
AU - Lavrijsen, Reinoud
AU - Verheijen, Marcel A.
AU - Zoethout, Erwin
AU - Genuit, Han
AU - van de Sanden, Mauritius C.M.
AU - Bieberle-Hütter, Anja
PY - 2019/5/28
Y1 - 2019/5/28
N2 - The water splitting activity of hematite is sensitive to the film processing parameters due to limiting factors such as a short hole diffusion length, slow oxygen evolution kinetics, and poor light absorptivity. In this work, we use direct current (DC) magnetron sputtering as a fast and cost-effective route to deposit metallic iron thin films, which are annealed in air to obtain well-adhering hematite thin films on F:SnO2-coated glass substrates. These films are compared to annealed hematite films, which are deposited by reactive radio frequency (RF) magnetron sputtering, which is usually used for depositing metal oxide thin films, but displays an order of magnitude lower deposition rate. We find that DC sputtered films have much higher photoelectrochemical activity than reactive RF sputtered films. We show that this is related to differences in the morphology and surface composition of the films as a result of the different processing parameters. This in turn results in faster oxygen evolution kinetics and lower surface and bulk recombination effects. Thus, fabricating hematite thin films by fast and cost-efficient metallic iron deposition using DC magnetron sputtering is shown to be a valid and industrially relevant route for hematite photoanode fabrication.
AB - The water splitting activity of hematite is sensitive to the film processing parameters due to limiting factors such as a short hole diffusion length, slow oxygen evolution kinetics, and poor light absorptivity. In this work, we use direct current (DC) magnetron sputtering as a fast and cost-effective route to deposit metallic iron thin films, which are annealed in air to obtain well-adhering hematite thin films on F:SnO2-coated glass substrates. These films are compared to annealed hematite films, which are deposited by reactive radio frequency (RF) magnetron sputtering, which is usually used for depositing metal oxide thin films, but displays an order of magnitude lower deposition rate. We find that DC sputtered films have much higher photoelectrochemical activity than reactive RF sputtered films. We show that this is related to differences in the morphology and surface composition of the films as a result of the different processing parameters. This in turn results in faster oxygen evolution kinetics and lower surface and bulk recombination effects. Thus, fabricating hematite thin films by fast and cost-efficient metallic iron deposition using DC magnetron sputtering is shown to be a valid and industrially relevant route for hematite photoanode fabrication.
UR - http://www.scopus.com/inward/record.url?scp=85066860430&partnerID=8YFLogxK
U2 - 10.1021/acsomega.8b03349
DO - 10.1021/acsomega.8b03349
M3 - Article
C2 - 31460015
AN - SCOPUS:85066860430
VL - 4
SP - 9262
EP - 9270
JO - ACS Omega
JF - ACS Omega
SN - 2470-1343
IS - 5
ER -