Study of How Photoelectrodes Modified by TiO2/Ag Nanofibers in Various Structures Enhance the Efficiency of Dye-Sensitized Solar Cells under Low Illumination

Abstract

Dye-sensitized solar cells (DSSCs) are low-cost solar cells belonging to the thin-film photovoltaic cell type. In this study, we studied the photovoltaic performances of DSSCs based on titanium dioxide (TiO2) nanofibers (NFs) containing silver (Ag) nanoparticles (NPs) under low illumination. We used the sol-gel method with the electrospinning technique to prepare the TiO2 NFs containing Ag NPs. Herein, we used two ways to add TiO2/Ag NFs to modify the photoelectrode successfully and enhance the performance of DSSCs. One way was that the TiO2/Ag NFs were mixed with pristine TiO2; the other way was that the TiO2/Ag NFs were seeded beside the TiO2 colloid layer as an additional layer on the photoelectrode of the DSSC. According to this experiment, the photovoltaic conversion efficiency of the DSSC which had TiO2/Ag NF seeded as an additional layer on the photoelectrode (5.13%) was increased by 28% compared to the DSSC without the photoelectrode modification (3.99%). This was due to the suppression of electron recombination and the more effective utilization of the light radiation by adding the TiO2/Ag NFs. Because of the good conductivity of Ag, the electrons were quickly transported and electron recombination was reduced. In addition, the photovoltaic conversion efficiency of the DSSC which had TiO2/Ag NF seeded as an additional layer on the photoelectrode increased from 5.13% to 6.23% during the decrease in illumination from 100 mW/cm2 to 30 mW/cm2; however, its photovoltaic conversion efficiency decreased to 5.31% when the illumination was lowered to 10 mW/cm2.

Towards Integration of Two-Dimensional Hexagonal Boron Nitride (2D h-BN) in Energy Conversion and Storage Devices

“…The anode material in DSSC should provide a high surface area in order to host a large number of photoactive dye molecules [174]. However, by increasing the surface area of TiO 2, the number of surface states increases, leading to higher rates of recombination [175]. Moreover, the heat treatment of TiO 2 at temperatures around 450 • C to form the anatase phase which is favorable for DSSC, leads to the formation of oxygen vacancies [176].…”

N719 dye as a sensitizer for dye‐sensitized solar cells (DSSCs): A review of its functions and certain rudimentary principles

“…Toward enhance light harvesting and reduce recombination loss, photoanode mesoporous layers have to be improved in term of thickness and light scattering ability. To accomplish this, Nien et al, 118 synthesized TiO 2 nano‐fibers containing silver (Ag) NPs (TNSN) by the sol–gel process for use as a photoanode in DSSC. Both TNSN and pristine TiO 2 were used in the preparation: first, TNSN was mixed with pristine TiO 2 and then the TiO 2 layer was covered with TNSN.…”

AgNWs@TiO2 and AgNPs@TiO2 Double-Layer Photoanode Film Improving Light Capture and Application under Low Illumination

“…According to Huang et al [29], the incident light power was too low under the illumination of 10 mW/cm 2 so that the electrons were intercepted by the oxidized electrolyte. Nien et al [30] showed that under low illumination, DSSCs can reduce the recombination reaction to enhance PCE, and the LSPR effect of AgNPs made more effective use of visible light radiation. In our work, under the low illumination of 10mW/cm 2 , the Schottky barrier interacting with AgNWs and TiO2 inhibited the recombination of charge and electrolyte, and the PCE increased to 8.78%.…”