%0 Journal Article
%A Shavorskiy, Andrey
%A Ye, Xiaofei
%A Karslıoğlu, Osman
%A Poletayev, Andrey D.
%A Hartl, Matthias
%A Zegkinoglou, Ioannis
%A Trotochaud, Lena
%A Nemšák, Slavomir
%A Schneider, Claus M.
%A Crumlin, Ethan J.
%A Axnanda, Stephanus
%A Liu, Zhi
%A Ross, Philip N.
%A Chueh, William
%A Bluhm, Hendrik
%T Direct Mapping of Band Positions in Doped and Undoped Hematite during Photoelectrochemical Water Splitting
%J The journal of physical chemistry letters
%V 8
%N 22
%@ 1948-7185
%C Washington, DC
%I ACS
%M FZJ-2018-00355
%P 5579 - 5586
%D 2017
%X Photoelectrochemical water splitting is a promising pathway for the direct conversion of renewable solar energy to easy to store and use chemical energy. The performance of a photoelectrochemical device is determined in large part by the heterogeneous interface between the photoanode and the electrolyte, which we here characterize directly under operating conditions using interface-specific probes. Utilizing X-ray photoelectron spectroscopy as a noncontact probe of local electrical potentials, we demonstrate direct measurements of the band alignment at the semiconductor/electrolyte interface of an operating hematite/KOH photoelectrochemical cell as a function of solar illumination, applied potential, and doping. We provide evidence for the absence of in-gap states in this system, which is contrary to previous measurements using indirect methods, and give a comprehensive description of shifts in the band positions and limiting processes during the photoelectrochemical reaction.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:29083905
%U <Go to ISI:>//WOS:000416291600019
%R 10.1021/acs.jpclett.7b02548
%U https://juser.fz-juelich.de/record/842074