Selective laser sintering of TiO2 nanoparticle film on plastic conductive substrate for highly efficient flexible dye-sensitized solar cell application

摘要

In this paper, we report a novel selective laser sintering of TiO2 nanoparticle (Degussa P25) film on plastic conductive substrates for highly efficient flexible dye-sensitized solar cell (DSC) applications. The so-called "selective sintering" means that the absorbed laser energy can effectively promote the electrical contacts between the TiO2 nanoparticles, but does not cause damage to the plastic conductive substrate. The choice of the near-infrared (wavelength = 1064 nm) laser source is critical for the effectiveness of the laser sintering. The laser sintering technology can effectively decrease electron transport resistance and increase recombination resistance of the TiO2 nanoparticle film characterized by electrochemical impedance spectroscopy and transient photovoltage/photocurrent decay measurements, resulting in much improved charge collection efficiency. Thus, compared to the reference sample, the laser sintered film has achieved an improved short-circuit current density from 9.2 to 10.4 mA cm~(-2), fill factor from 0.71 to 0.77, and solar conversion efficiency from 4.5% to 5.7%. The fast and effective selective laser sintering technique has great potential to be integrated into scalable roll-to-roll manufacturing of highly efficient flexible DSCs.