Full-Space Potential Gradient Driven Charge Migration inside BiFeO3Photocathode
Por:
Tan B., Reyes A.M., Menéndez-Proupin E., Reyes-Lillo S.E., Li Y., Zhang Z.
Publicada:
1 ene 2022
Resumen:
Solar-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. © 2022 American Chemical Society.
Filiaciones:
Tan B.:
School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
Reyes A.M.:
Departamento de Ciencias Físicas, Universidad Andres Bello, Santiago, 837-0136, Chile
Centro de Excelencia en Nuevos Materiales (CENM) y Departamento de Física, Grupo de Óptica Cuántica, Universidad Del Valle, Santiago de Cali, A.A. 25360, Colombia
Menéndez-Proupin E.:
Departamento de Física Aplicada, Escuela Politécnica Superior, Universidad de Sevilla, Seville, E-41011, Spain
Reyes-Lillo S.E.:
Departamento de Ciencias Físicas, Universidad Andres Bello, Santiago, 837-0136, Chile
Li Y.:
Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 610054, China
Zhang Z.:
School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
All Open Access; Green Open Access
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