Tan, BingReyes, Abdul M.Menéndez-Proupin, EduardoReyes-Lillo, Sebastián E.Li, YanboZhang, Zemin2024-04-232024-04-232022-092380-8195https://hdl.handle.net/11441/156997Solar–fuel conversion depends on effective collection of photocarriers in the photoelectrode. In practice, however, considerable photocarriers are lost in the bulk through recombination due to the absence of a driving force. To overcome this, herein, a full-space electric field is induced in BiFeO₃ photocathodes by building a gradient homojunction through Fermi level engineering. As expected, the BiFeO₃ photocathodes with forward electric field show significantly enhanced performance: a state-of-the-art photocurrent of −1.02 mA·cm⁻² at 0.5 V vs RHE and H₂O₂ production of 380 mmol·(L·m²)⁻¹ within 50 min. First-principles calculations and experimental analysis suggest that the Bi vacancies as shallow acceptors can significantly modulate the Fermi level of BiFeO₃. The resulting internal electric field serves as an additional driving force to promote charge collection. This work provides an approach to induce a full-space electric field in semiconductor films through gradient defects modulation, which can be broadly applied to other optoelectronic systems.application/pdf8 p.engAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Bismuth ferriteDefects in solidsElectric fieldsPhotonicsThin filmsShow Lessinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccesshttps://doi.org/10.1021/acsenergylett.2c01750