Search

• CdS under-layer reduces the recombination at Ag 2 S/FTO interface. • Photoinduced charge carrier dynamics of FTO/CdS/Ag 2 S has been studied. • CdS under-layer raise 52% PCE of Ag 2 S solar cell. [Display omitted] The recombination of photoinduced charge carriers is detrimental to the photovoltaic performance of solar cells. In this work, we used CdS as an under-layer to reduce the recombination of photoinduced charge carriers at the Ag 2 S/FTO (F-doped SnO 2) interface. The CdS under-layer was deposited onto an FTO substrate using a facile chemical bath deposition (CBD) method. By controlling the thickness of the CdS film between Ag 2 S and FTO, the recombination of photoinduced charge carriers was successfully suppressed. The effect of the CdS under-layer on the charge carrier recombination was carefully evaluated by transient surface photovoltage (TSPV) measurements, electrochemical impedance spectroscopy (EIS) and a photoelectrochemical method. The power conversion efficiency (PCE) of solar cell devices with a 40 nm CdS under-layer is 1.16%, which is ~52% enhancement compared to those of FTO/Ag 2 S-based solar cell devices. Our work may provide a useful strategy to suppress photoinduced charge carrier recombination at the electrode and absorber semiconductor interface. [ABSTRACT FROM AUTHOR]

• Nanosheets CuO and nanorods ZnO construct heterojunction material. • CuO / ZnO shows wavelength dependent charge carrier dynamics. • Photogenerated holes in CuO / ZnO may determine catalytic performance. Heterojunction materials composed of narrow and wide band-gap semiconductors possess different photoelectric responses under different wavelength incident light, and show distinct photogenerated charge carrier dynamics. In this work, taking the hydrothermal method fabricated CuO nanosheets / ZnO nanorods heterojunction materials as example, the wavelength dependent photoinduced charge carrier dynamics in this heterojunction material have been carefully studied. Transient surface photovoltage (TSPV) measurements reveal that the photogenerated holes gather at the surface of the fabricated CuO / ZnO with 355 nm light illumination, but photogenerated electrons gather at the surface under 532 nm light. Photocatalytic degradation experiments suggest that CuO / ZnO heterojunction material has better performance under ultraviolet light than that under visible light. [ABSTRACT FROM AUTHOR]