DC sputter deposited TiO.sub.2 layers on FTO: towards a maximum photoelectrochemical response of photoanodes

• Published in: Journal of materials science Vol. 57; no. 27; pp. 12960 - 12970
• Main Authors: Kim, Hyesung, Wang, Yue, Denisov, Nikita, Wu, Zhenni, Kment, Stepán, Schmuki, Patrik
• Format: Journal Article
• Language: English
• Published: Springer 01.07.2022
• Subjects: Annealing
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-022-07420-4

In this work, we examine the photoelectrochemical response of TiO.sub.2 layers prepared by reactive DC sputter deposition on conductive glass (FTO). We show that adequate conditioning of the FTO by a very thin (few nm thick) Ti interlayer and optimizing the sputter parameters, compact TiO.sub.2 anatase layers can be produced that reach incident photocurrent conversion efficiencies (IPCE) maxima peaking at 75%. This is outperforming many of the best titania photoanode structures (including high surface area 1D and 3D titania structures). The key role of the interlayer is to promote the crystallization of titania in the anatase form during the annealing process (as opposed to rutile in the interlayer-free case). Without this interlayer, an IPCE maxima of [almost equal to]43% is obtained for otherwise identically processed electrodes. The present work thus describes a most simple straightforward approach for fabricating compact, high-efficiency TiO.sub.2 (anatase) photoanodes.