TiO₂ Antireflection Coating Deposited by Electro-Beam Evaporation: Thin Film Thickness Effect on Weighted Reflectance and Surface Passivation of Silicon Solar Cells

Titanium dioxide was extensively used in solar cell industry and currently has been studied to produce passivated contacts in PERC/PERT and TOPCon solar cells. The aim of this paper was to analyze the impact of the thickness of TiO₂ thin films deposited by electro-beam evaporation on the weighted reflectance and the surface passivation on silicon solar cells. Thin films with different thicknesses were deposited to produce PERT solar cells, varying from 50 to 90 nm. The surface passivation was enhanced as the thickness was increased. For instance, at 400 nm, the internal quantum efficiency increased from 71% to 76% when the thickness of the TiO₂ was augmented from 50 nm to 90 nm. The lowest weighted reflectance was obtained in samples with 80 nm thick TiO₂ films. Considering the compromise between antireflection properties and surface passivation, the highest efficiency solar cells were produced with 80 nm thick TiO₂.

Keywords:
Silicon solar cells; titanium dioxide; antireflection coating; surface passivation