Photoelectrochemical water splitting with a SrTiO3:Nb/SrTiO3 n+-n homojunction structure

Jiajie Cen; Qiyuan Wu; Danhua Yan; Jing Tao; Kim Kisslinger; Mingzhao Liu; Alexander Orlov

doi:10.1039/c6cp07111b

Photoelectrochemical water splitting with a SrTiO₃:Nb/SrTiO₃ n⁺-n homojunction structure

Phys Chem Chem Phys. 2017 Jan 25;19(4):2760-2767. doi: 10.1039/c6cp07111b.

Authors

Jiajie Cen¹, Qiyuan Wu¹, Danhua Yan², Jing Tao³, Kim Kisslinger⁴, Mingzhao Liu⁴, Alexander Orlov¹

Affiliations

¹ Department of Materials and Science Engineering, Stony Brook University, Stony Brook, New York 11794, USA. alexander.orlov@stonybrook.edu.
² Department of Materials and Science Engineering, Stony Brook University, Stony Brook, New York 11794, USA. alexander.orlov@stonybrook.edu and Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA. mzliu@bnl.gov.
³ Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
⁴ Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA. mzliu@bnl.gov.

PMID: 28067360
DOI: 10.1039/c6cp07111b

Abstract

A very limited knowledge exists about the effect of non-uniform doping of epitaxially grown strontium titanate thin film electrodes on their photoelectrochemical performance in water splitting. In this work, water splitting photoanodes featuring an n⁺-n homojunction were fabricated by the pulsed laser deposition technique, where epitaxial SrTiO₃ thin films were grown on Nb doped n⁺-SrTiO₃ single crystalline substrates. Thermal diffusion of niobium from doped substrates into the deposited thin films formed an n⁺-n homojunction, which was profiled by angle-resolved XPS and cross-sectional STEM-EDX techniques. This homojunction was found to make a significant impact on the incident photon-to-current efficiency of photoanodes by affecting their depletion width, which was in agreement with the theoretical simulations.