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[Display omitted] Metal-organic polymers (MOPs) can enhance the photoelectrochemical (PEC) water oxidation performance of BiVO 4 photoanodes, but their PEC mechanisms have yet to be comprehended. In this work, we constructed an active and stable composite photoelectrode by overlaying a uniform MOP on the BiVO 4 surface using Fe2+ as the metal ions and 2,5-dihydroxyterephthalic acid (DHTA) as ligand. Such modification on the BiVO 4 surface yielded a core-shell structure that could effectively enhance the PEC water oxidation activity of the BiVO 4 photoanode. Our intensity-modulated photocurrent spectroscopy analysis revealed that the MOP overlayer could concurrently reduce the surface charge recombination rate constant (k sr) and enhance the charge transfer rate constant (k tr), thus accelerating water oxidation activity. These phenomena can be ascribed to the passivation of the surface that inhibits the recombination of the charge carrier and the MOP catalytic layer that improves the hole transfer. Our rate law analysis also demonstrated that the MOP coverage shifted the reaction order of the BiVO 4 photoanode from the third-order to the first-order, resulting in a more favorable rate-determining step where only one hole accumulation is required to overcome water oxidation. This work provides new insights into the reaction mechanism of MOP-modified semiconductor photoanodes. [ABSTRACT FROM AUTHOR]

Although hybrid solar cells take advantages of both inorganic and organic semiconductors for high performance, there have not been comparably photoelectric conversion efficiencies as expected from this kind of solar cells till now. The photoelectric response behavior of inorganic/organic hybrid solar cells has been explained on the theory of inorganic solar cells, but the distinctive wavelength dependent photoelectric character of organic semiconductors has not been well considered. In this work, Ag 2 S/organic bulk heterojunction solar cell devices were designed and fabricated in-situ on indium tin oxide (ITO) based on the direct metal surface elemental reaction (DMSER) method, to understand the corresponding photoinduced charge carrier dynamics under different wavelength light. The commonly used small molecule Spiro-OMeTAD and polymeric PTB7-Th were selected as the organic components of the fabricated solar cells. In Ag 2 S/Spiro-OMeTAD, Ag 2 S donated the charge carriers and controlled the photoinduced charge carrier dynamics of the devices at both 355 nm and 532 nm lights. Under 532 nm light, the PTB7-Th acted as hole transport materials (HTM) rather than charge carrier donor. These results indicated that hybrid thin films without wavelength dependent charge carrier dynamics is preferred for high performance solar cells. [ABSTRACT FROM AUTHOR]