TY - JOUR
T1 - Modulation of Surface Bonding Topology
T2 - Oxygen Bridges on OH-Terminated InP (001)
AU - Zhang, Xueqiang
AU - Pham, Tuan Anh
AU - Ogitsu, Tadashi
AU - Wood, Brandon C.
AU - Ptasinska, Sylwia
N1 - Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/2/6
Y1 - 2020/2/6
N2 - An understanding and control of complex physiochemical processes at the photoelectrode/electrolyte interface in photoelectrochemical cells (PECs) are essential for developing advanced solar-driven water-splitting technology. Here, we integrate ambient pressure X-ray photoelectron spectroscopy (APXPS) and high-level first-principles calculations to elucidate the evolution of the H2O/InP (001) interfacial chemistry under in situ and ambient conditions. In addition to molecular H2O, OH and H are the only two species found on InP (001) at room temperature. Under elevated temperatures, although the formation of In-O-P is thermodynamically more favorable over In-O-In, the latter can be preferentially generated in a kinetically driven and nonequilibrated environment such as ultrahigh vacuum (UHV); however, when InP is exposed to H2O at both elevated pressures and temperatures, its surface chemistry becomes thermodynamically driven and only In-O-P (or POx) oxygen bridges form. Our simulations suggest that In-O-In, rather than In-O-P, constitutes a charge carrier (hole) trap that causes photocorrosion in PEC devices. Therefore, understanding and modulating the chemical nature of oxygen bridges at the H2O/InP (001) interface will shed light on the fabrication of InP-based photoelectrodes with simultaneously enhanced stability and efficiency.
AB - An understanding and control of complex physiochemical processes at the photoelectrode/electrolyte interface in photoelectrochemical cells (PECs) are essential for developing advanced solar-driven water-splitting technology. Here, we integrate ambient pressure X-ray photoelectron spectroscopy (APXPS) and high-level first-principles calculations to elucidate the evolution of the H2O/InP (001) interfacial chemistry under in situ and ambient conditions. In addition to molecular H2O, OH and H are the only two species found on InP (001) at room temperature. Under elevated temperatures, although the formation of In-O-P is thermodynamically more favorable over In-O-In, the latter can be preferentially generated in a kinetically driven and nonequilibrated environment such as ultrahigh vacuum (UHV); however, when InP is exposed to H2O at both elevated pressures and temperatures, its surface chemistry becomes thermodynamically driven and only In-O-P (or POx) oxygen bridges form. Our simulations suggest that In-O-In, rather than In-O-P, constitutes a charge carrier (hole) trap that causes photocorrosion in PEC devices. Therefore, understanding and modulating the chemical nature of oxygen bridges at the H2O/InP (001) interface will shed light on the fabrication of InP-based photoelectrodes with simultaneously enhanced stability and efficiency.
UR - http://www.scopus.com/inward/record.url?scp=85079758163&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.9b11548
DO - 10.1021/acs.jpcc.9b11548
M3 - Article
AN - SCOPUS:85079758163
SN - 1932-7447
VL - 124
SP - 3196
EP - 3203
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 5
ER -