UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Heteroepitaxy of GaP on silicon for efficient and cost-effective photoelectrochemical water splitting

Alqahtani, M; Sathasivam, S; Cui, F; Steier, L; Xia, X; Blackman, C; Kim, E; ... Wu, J; + view all (2019) Heteroepitaxy of GaP on silicon for efficient and cost-effective photoelectrochemical water splitting. Journal of Materials Chemistry A , 7 (14) pp. 8550-8558. 10.1039/c9ta01328h. Green open access

[thumbnail of Liu GaP(journal of materials chemistry A)-updated.pdf]
Preview
Text
Liu GaP(journal of materials chemistry A)-updated.pdf - Accepted Version

Download (1MB) | Preview

Abstract

Photoelectrochemical production of hydrogen by using sunlight to split water offers a sustainable approach for clean energy generation. III-V Semiconductors have shown the highest efficiencies for photoelectrochemical water splitting but the prohibitive cost of commercial single-crystalline GaP wafers limit practical use and large-scale application. Here, we report a high-quality GaP photocathode directly grown on a silicon substrate by solidsource molecular beam epitaxy. The photocathode can be stabilized under acidic electrolyte 1M HClO4 (pH 0) by a combined an amorphous TiO2 layer coated with a molybdenum sulphide MoS2 hydrogen evolution catalyst by atomic layer deposition (ALD). Under simulated AM 1.5G solar illumination, the Si/GaP photocathode yielded a maximum photocurrent density of 0.95 (mA/ cm2 ) with a proton reduction onset potential was 467 mV versus the reversible hydrogen electrode. The average Faradaic efficiency of the Si/GaP photocathode was measured to be over 73.4±20.2% for over 100 minutes. The photoelectrochemical studies for the Si/GaP photocathode show the potential for widespread deployment of cost-effective photoelectrodes for hydrogen generation.

Type: Article
Title: Heteroepitaxy of GaP on silicon for efficient and cost-effective photoelectrochemical water splitting
Open access status: An open access version is available from UCL Discovery
DOI: 10.1039/c9ta01328h
Publisher version: https://doi.org/10.1039/c9ta01328h
Language: English
Additional information: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Chemical Engineering
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Electronic and Electrical Eng
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry
URI: https://discovery.ucl.ac.uk/id/eprint/10073808
Downloads since deposit
80Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item