Scalable, highly stable Si-based metal-insulator-semiconductor photoanodes for water oxidation fabricated using thin-film reactions and electrodeposition

Date
2021-06-25
Authors
Lee, Soonil
Ji, Li
De Palma, Alex C.
Yu, Edward T.
Journal Title
Journal ISSN
Volume Title
Publisher
Springer Nature Limited
Abstract

Metal-insulator-semiconductor (MIS) structures are widely used in Si-based solar water- splitting photoelectrodes to protect the Si layer from corrosion. Typically, there is a tradeoff between efficiency and stability when optimizing insulator thickness. Moreover, lithographic patterning is often required for fabricating MIS photoelectrodes. In this study, we demon- strate improved Si-based MIS photoanodes with thick insulating layers fabricated using thin- film reactions to create localized conduction paths through the insulator and electro- deposition to form metal catalyst islands. These fabrication approaches are low-cost and highly scalable, and yield MIS photoanodes with low onset potential, high saturation current density, and excellent stability. By combining this approach with a p

+n-Si buried junction, further improved oxygen evolution reaction (OER) performance is achieved with an onset potential of 0.7 V versus reversible hydrogen electrode (RHE) and saturation current density of 32 mA/cm

2 under simulated AM1.5G illumination. Moreover, in stability testing in 1 M KOH aqueous solution, a constant photocurrent density of ~22 mA/cm

2 is maintained at 1.3

V versus RHE for 7 days.

Description
Citation
Lee, S., Ji, L., De Palma, A.C. et al. Scalable, highly stable Si-based metal-insulator-semiconductor photoanodes for water oxidation fabricated using thin-film reactions and electrodeposition. Nat Commun 12, 3982 (2021). https://doi.org/10.1038/s41467-021-24229-y