Surface modification of silicon solar cell using TiO2 and Ta2O5: fabrication and characterization

We report the fabrication and characterization of surface modified silicon solar cells with the deposition of amorphous tantalum oxide (Ta2O5) and crystalline titanium oxide (TiO2) nanolayers of thickness 54.9 nm and 69.82 nm, respectively, as antireflection coating (ARC) using RF-sputtering technique. The thickness of the films measured by variable angle spectroscopic ellipsometry and scanning electron microscopy is in close agreement. The transmittance measurement as a function of wavelength of incident light showed that the thin-films deposited have lowest effective reflectance in the wavelength range of 380 nm–570 nm indicating reduced light reflection and enhanced light trapping as observed from UV–Vis measurements. Illuminated current–voltage measurements showed an increase in the short circuit current density (Jsc) and an increase of 1.54% in the efficiency of the antireflection-coated cells. Results of the External Quantum Efficiency measurement as a function of wavelength for the solar cells with ARC is also presented in this paper.