Interface engineering of Ta3N5 thin film photoanode for highly efficient photoelectrochemical water splitting

Jie Fu; Zeyu Fan; Mamiko Nakabayashi; Huanxin Ju; Nadiia Pastukhova; Yequan Xiao; Chao Feng; Naoya Shibata; Kazunari Domen; Yanbo Li

doi:10.1038/s41467-022-28415-4

Interface engineering of Ta₃N₅ thin film photoanode for highly efficient photoelectrochemical water splitting

Nat Commun. 2022 Feb 7;13(1):729. doi: 10.1038/s41467-022-28415-4.

Authors

Jie Fu¹, Zeyu Fan^{1

2}, Mamiko Nakabayashi³, Huanxin Ju⁴, Nadiia Pastukhova¹, Yequan Xiao¹, Chao Feng¹, Naoya Shibata³, Kazunari Domen^{5

6}, Yanbo Li^{7

8}

Affiliations

¹ Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, China.
² Yangtza Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, China.
³ Institute of Engineering Innovation, The University of Tokyo, Tokyo, Japan.
⁴ PHI China Analytical Laboratory, CoreTech Integrated Limited, Nanjing, China.
⁵ Office of University Professors, The University of Tokyo, Tokyo, Japan.
⁶ Research Initiative for Supra-Materials (RISM), Shinshu University, Nagano, Japan.
⁷ Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, China. [email protected].
⁸ Yangtza Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, China. [email protected].

Abstract

Interface engineering is a proven strategy to improve the efficiency of thin film semiconductor based solar energy conversion devices. Ta₃N₅ thin film photoanode is a promising candidate for photoelectrochemical (PEC) water splitting. Yet, a concerted effort to engineer both the bottom and top interfaces of Ta₃N₅ thin film photoanode is still lacking. Here, we employ n-type In:GaN and p-type Mg:GaN to modify the bottom and top interfaces of Ta₃N₅ thin film photoanode, respectively. The obtained In:GaN/Ta₃N₅/Mg:GaN heterojunction photoanode shows enhanced bulk carrier separation capability and better injection efficiency at photoanode/electrolyte interface, which lead to a record-high applied bias photon-to-current efficiency of 3.46% for Ta₃N₅-based photoanode. Furthermore, the roles of the In:GaN and Mg:GaN layers are distinguished through mechanistic studies. While the In:GaN layer contributes mainly to the enhanced bulk charge separation efficiency, the Mg:GaN layer improves the surface charge inject efficiency. This work demonstrates the crucial role of proper interface engineering for thin film-based photoanode in achieving efficient PEC water splitting.

Abstract

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