Band alignment of TiO2/FTO interface determined by X-ray photoelectron spectroscopy: Effect of annealing

Haibo Fan; Zhou Yang; Xianpei Ren; Mingli Yin; Fei Gao; Shengzhong (Frank) Liu

doi:10.1063/1.4941040

AIP Advances (Jan 2016)

Band alignment of TiO2/FTO interface determined by X-ray photoelectron spectroscopy: Effect of annealing

Haibo Fan,
Zhou Yang,
Xianpei Ren,
Mingli Yin,
Fei Gao,
Shengzhong (Frank) Liu

Affiliations

Haibo Fan: Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education; Shaanxi Engineering Lab for Advanced Energy Technology; School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710119, China
Zhou Yang: Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education; Shaanxi Engineering Lab for Advanced Energy Technology; School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710119, China
Xianpei Ren: Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education; Shaanxi Engineering Lab for Advanced Energy Technology; School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710119, China
Mingli Yin: Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education; Shaanxi Engineering Lab for Advanced Energy Technology; School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710119, China
Fei Gao: Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education; Shaanxi Engineering Lab for Advanced Energy Technology; School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710119, China
Shengzhong (Frank) Liu: Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education; Shaanxi Engineering Lab for Advanced Energy Technology; School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710119, China

DOI: https://doi.org/10.1063/1.4941040
Journal volume & issue: Vol. 6, no. 1
pp. 015314 – 015314-7

Abstract

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The energy band alignment between pulsed-laser-deposited TiO2 and FTO was firstly characterized using high-resolution X-ray photoelectron spectroscopy. A valence band offset (VBO) of 0.61 eV and a conduction band offset (CBO) of 0.29 eV were obtained across the TiO2/FTO heterointerface. With annealing process, the VBO and CBO across the heterointerface were found to be -0.16 eV and 1.06 eV, respectively, with the alignment transforming from type-I to type-II. The difference in the band alignment is believed to be dominated by the core level down-shift of the FTO substrate, which is a result of the oxidation of Sn. Current-voltage test has verified that the band alignment has a significant effect on the current transport of the heterojunction.

Published in AIP Advances

ISSN: 2158-3226 (Online)
Publisher: AIP Publishing LLC
Country of publisher: United States
LCC subjects: Science: Physics
Website: http://aipadvances.aip.org/

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