Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 1, 2015 | Published + Supplemental Material
Journal Article Open

Direct observation of the energetics at a semiconductor/liquid junction by operando X-ray photoelectron spectroscopy

Abstract

Photoelectrochemical (PEC) cells based on semiconductor/liquid interfaces provide a method of converting solar energy to electricity or fuels. Currently, the understanding of semiconductor/liquid interfaces is inferred from experiments and models. Operando ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) has been used herein to directly characterize the semiconductor/liquid junction at room temperature under real-time electrochemical control. X-ray synchrotron radiation in conjunction with AP-XPS has enabled simultaneous monitoring of the solid surface, the solid/electrolyte interface, and the bulk electrolyte of a PEC cell as a function of the applied potential, U. The observed shifts in binding energy with respect to the applied potential have directly revealed ohmic and rectifying junction behavior on metallized and semiconducting samples, respectively. Additionally, the non-linear response of the core level binding energies to changes in the applied electrode potential has revealed the influence of defect-derived electronic states on the Galvani potential across the complete cell.

Additional Information

© 2015 Royal Society of Chemistry. Received 30th March 2015; accepted 29th May 2015. First published online 29 May 2015. This work was supported through the Office of Science of the U.S. Department of Energy (DOE) under award no. DE-SC0004993 to the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract no. DE-AC02-05CH11231. We acknowledge Dr. Philip Ross for his contributions to the conceptual development of the AP-XPS endstation and experimental design, and Junko Yano for fruitful discussions. We acknowledge Fadl Saadi, Beomgyun Jeong, and Sana Rani for assistance during data collection at the beamline.

Attached Files

Published - c5ee01014d.pdf

Supplemental Material - c5ee01014d1.pdf

Files

c5ee01014d1.pdf
Files (3.8 MB)
Name Size Download all
md5:b747f642c02f0af7bafa763977ce117c
1.4 MB Preview Download
md5:71a58527d7be33f95f4e4cbc570a448a
2.5 MB Preview Download

Additional details

Created:
August 20, 2023
Modified:
October 23, 2023