Excimer laser annealing of TIO2 nanoparticles for dye sensitized solar cells

Abstract

We report a rapid and low temperature process for fabricating composite TiO2 electrodes for dye-sensitized solar cells (DSSCs) on glass and plastics by in-tandem spray deposition and laser annealing. A homogenized KrF excimer laser beam (248nm) was used to layer-by-layer anneal spray deposited TiO2 nanoparticles. The produced TiO2 film is crack free and contains small particles (30nm) mixed with different fractions of larger particles (100-200nm) controlled by the applied laser fluence. Laser annealed double-layered structure is demonstrated for both doctor-blade deposited and spray-deposited electrodes and performance enhancement can be observed. The enhancement could come from the laser induced optical and electrical properties changes. The highest demonstrated all-laser-annealed cells utilizing Ruthenium dye and liquid electrolyte showed power conversion efficiency of ∼3.8% under simulated illumination of 100mW/cm2.