TY - JOUR
T1 - Direct observation of the energetics at a semiconductor/liquid junction by operando X-ray photoelectron spectroscopy
AU - Lichterman, Michael F.
AU - Hu, Shu
AU - Richter, Matthias H.
AU - Crumlin, Ethan J.
AU - Axnanda, Stephanus
AU - Favaro, Marco
AU - Drisdell, Walter
AU - Hussain, Zahid
AU - Mayer, Thomas
AU - Brunschwig, Bruce S.
AU - Lewis, Nathan S.
AU - Liu, Zhi
AU - Lewerenz, Hans Joachim
N1 - Publisher Copyright:
© The Royal Society of Chemistry 2015.
Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2015
Y1 - 2015
N2 - 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.
AB - 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.
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U2 - 10.1039/c5ee01014d
DO - 10.1039/c5ee01014d
M3 - Article
AN - SCOPUS:84938329372
VL - 8
SP - 2409
EP - 2416
JO - Energy and Environmental Science
JF - Energy and Environmental Science
SN - 1754-5692
IS - 8
ER -