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Enhancing Charge Carrier Lifetime in Metal Oxide Photoelectrodes through Mild Hydrogen Treatment
Author(s) -
Jang JiWook,
Friedrich Dennis,
Müller Sönke,
Lamers Marlene,
Hempel Hannes,
Lardhi Sheikha,
Cao Zhen,
Harb Moussab,
Cavallo Luigi,
Heller René,
Eichberger Rainer,
van de Krol Roel,
Abdi Fatwa F.
Publication year - 2017
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201701536
Subject(s) - materials science , passivation , charge carrier , bismuth vanadate , carrier lifetime , oxide , doping , hydrogen , electron mobility , bismuth , dopant , optoelectronics , nanotechnology , photocatalysis , silicon , chemistry , metallurgy , biochemistry , organic chemistry , layer (electronics) , catalysis
Widespread application of solar water splitting for energy conversion is largely dependent on the progress in developing not only efficient but also cheap and scalable photoelectrodes. Metal oxides, which can be deposited with scalable techniques and are relatively cheap, are particularly interesting, but high efficiency is still hindered by the poor carrier transport properties (i.e., carrier mobility and lifetime). Here, a mild hydrogen treatment is introduced to bismuth vanadate (BiVO 4 ), which is one of the most promising metal oxide photoelectrodes, as a method to overcome the carrier transport limitations. Time‐resolved microwave and terahertz conductivity measurements reveal more than twofold enhancement of the carrier lifetime for the hydrogen‐treated BiVO 4 , without significantly affecting the carrier mobility. This is in contrast to the case of tungsten‐doped BiVO 4 , although hydrogen is also a donor type dopant in BiVO 4 . The enhancement in carrier lifetime is found to be caused by significant reduction of trap‐assisted recombination, either via passivation or reduction of deep trap states related to vanadium antisite on bismuth or vanadium interstitials according to density functional theory calculations. Overall, these findings provide further insights on the interplay between defect modulation and carrier transport in metal oxides, which benefit the development of low‐cost, highly‐efficient solar energy conversion devices.