Thickness-Dependent Photoelectrochemical Water Splitting on Ultrathin LaFeO3 Films Grown on Nb:SrTiO3

The performance of photoelectrodes can be modified by changing the material chemistry, geometry, and interface engineering. Specifically, nanoscale active layers can facilitate the collection of charge carriers. In heterostructure devices, the multiple material interfaces are particularly important,...

Full description

Saved in:
Bibliographic Details
Published inThe journal of physical chemistry letters Vol. 6; no. 6; pp. 977 - 985
Main Authors May, Kevin J, Fenning, David P, Ming, Tian, Hong, Wesley T, Lee, Dongkyu, Stoerzinger, Kelsey A, Biegalski, Michael D, Kolpak, Alexie M, Shao-Horn, Yang
Format Journal Article
LanguageEnglish
Published United States American Chemical Society 19.03.2015
Subjects
CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
oxide interfaces
oxygen evolution
perovskites
photoelectrochemistry
thin films
water splitting
perovskites
photoelectrochemistry
water splitting
oxygen evolution
oxide interfaces
thin films
Online AccessGet full text

Cover

More Information
Summary:The performance of photoelectrodes can be modified by changing the material chemistry, geometry, and interface engineering. Specifically, nanoscale active layers can facilitate the collection of charge carriers. In heterostructure devices, the multiple material interfaces are particularly important, which at present are not well understood for oxides. Here, we report a detailed study of ultrathin (2–25 nm) LaFeO3 films grown epitaxially on Nb-doped SrTiO3. The films exhibit thickness-dependence with sensitivity to less than 10 nm in both the through-plane charge transfer conductivity and in the potential-dependent photoresponse. Supplementing photoelectrochemical measurements with X-ray photoelectron spectroscopy, spectroscopic ellipsometry, and electrochemical impedance spectroscopy, we construct a band model that accounts for this thickness dependence via a shifting valence-band offset at the film–substrate interface and the potential-dependent overlap of the depletion regions present at both the film–substrate and film-electrolyte interfaces. These results illustrate the utility of using active layer thickness and film–substrate interactions to tune the performance of photoelectrodes, providing insight for the design of efficient heterostructure oxide photoelectrochemical devices.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
USDOE Office of Science (SC)
AC05-00OR22725
ISSN:1948-7185
1948-7185
DOI:10.1021/acs.jpclett.5b00169