Header

UZH-Logo

Maintenance Infos

Interfacial Dipole Layer Enables High-Performance Heterojunctions for Photoelectrochemical Water Splitting


Yun, Juwon; Tan, Jeiwan; Jung, Young-Kwang; Yang, Wooseok; Lee, Hyungsoo; Ma, Sunihl; Park, Young Sun; Lee, Chan Uk; Niu, Wenzhe; Lee, Jeongyoub; Kim, Kyungmin; Tilley, S David; Walsh, Aron; Moon, Jooho (2022). Interfacial Dipole Layer Enables High-Performance Heterojunctions for Photoelectrochemical Water Splitting. ACS Energy Letters, 7:1392-1402.

Abstract

TiO2 has been widely used as an n-type overlayer, simultaneously serving as a protective layer for photocathodes. However, the photovoltage generated from a TiO2 junction with p-type absorbers, such as p-Si, Sb2Se3, SnS, and Cu2O, is insufficient. We report a dipole reorientation strategy to overcome this limitation by inserting a polyethylenimine ethoxylated (PEIE) layer between a p-type absorber and TiO2. Furthermore, we demonstrate that the PEIE dipole orientation can be rearranged by increasing the layer thickness, leading to an upward shift of the TiO2 band edge. The magnitude of band shift induced by the dipole effect depends on the TiO2 layer thickness. Using this approach, the onset potential was significantly improved to 0.5 V versus the reversible hydrogen electrode (VRHE) in a p-Si/PEIE/TiO2/Pt device. The versatility of the effective dipole reorientation strategy was demonstrated by application to a range of TiO2-protected heterojunction photocathodes based on Sb2Se3, Cu2O, and SnS.

Abstract

TiO2 has been widely used as an n-type overlayer, simultaneously serving as a protective layer for photocathodes. However, the photovoltage generated from a TiO2 junction with p-type absorbers, such as p-Si, Sb2Se3, SnS, and Cu2O, is insufficient. We report a dipole reorientation strategy to overcome this limitation by inserting a polyethylenimine ethoxylated (PEIE) layer between a p-type absorber and TiO2. Furthermore, we demonstrate that the PEIE dipole orientation can be rearranged by increasing the layer thickness, leading to an upward shift of the TiO2 band edge. The magnitude of band shift induced by the dipole effect depends on the TiO2 layer thickness. Using this approach, the onset potential was significantly improved to 0.5 V versus the reversible hydrogen electrode (VRHE) in a p-Si/PEIE/TiO2/Pt device. The versatility of the effective dipole reorientation strategy was demonstrated by application to a range of TiO2-protected heterojunction photocathodes based on Sb2Se3, Cu2O, and SnS.

Statistics

Citations

Dimensions.ai Metrics
10 citations in Web of Science®
10 citations in Scopus®
Google Scholar™

Altmetrics

Additional indexing

Item Type:Journal Article, refereed, further contribution
Communities & Collections:07 Faculty of Science > Department of Chemistry
Dewey Decimal Classification:540 Chemistry
Scopus Subject Areas:Physical Sciences > Chemistry (miscellaneous)
Physical Sciences > Renewable Energy, Sustainability and the Environment
Physical Sciences > Fuel Technology
Physical Sciences > Energy Engineering and Power Technology
Physical Sciences > Materials Chemistry
Uncontrolled Keywords:Materials Chemistry, Energy Engineering and Power Technology, Fuel Technology, Renewable Energy, Sustainability and the Environment, Chemistry (miscellaneous)
Language:English
Date:22 March 2022
Deposited On:30 Mar 2022 14:20
Last Modified:26 Feb 2024 02:51
Publisher:American Chemical Society (ACS)
ISSN:2380-8195
OA Status:Closed
Publisher DOI:https://doi.org/10.1021/acsenergylett.2c00392
Full text not available from this repository.