Antireflection properties of graphene layers on planar and textured silicon surfaces

In this study, theoretical and experimental investigations have been carried out to explore the suitability of graphene layers as an antireflection coating. Microwave plasma enhanced chemical vapor deposition and chemically grown graphene layers deposited on polished and textured silicon surfaces show that graphene deposition results in a large decrease in reflectance in the wavelength range of 300-650 nm, especially in the case of polished silicon. A Si3N4 /textured silicon reference antireflection coating and graphene deposited polished and textured silicon exhibit similar reflectance values, with the graphene/Si surface showing lower reflectance in the 300-400 nm range. Comparison of experimental results with the finite difference time domain calculations shows that the graphene along with a SiO2 surface layer results in a decrease in reflectance in the 300-650 nm range, with a reflectance value of < 5% for the case of graphene deposited textured silicon surfaces. The monolayer and inert character along with the high transmittance of graphene make it an ideal surface layer. The results of the present study show its suitability as an antireflection coating in solar cell and UV detector applications.