In this paper, we report a design of graphene/silicon thin film solar cell with novel array of textured dielectric-metal rear side reflector. In order to minimize the surface recombination, parasitic absorption losses and to increase rear reflections, a unique design of rear side of solar cell reflector is explored. Our proposed structure geometry has achieved extreme light trapping ability, maximum rear reflections and high inner scattering, result in absorption up to 90% at 40º angle of incidence when 1nm thick graphene used on the top and textured SiO2-Ag were used as dielectric-metal back reflector. Contrasted with the analogous reference cell devices, the light absorption in proposed textured solar cell with back dielectric-metal reflector is essentially improved from visible to infrared region from 600nm to 1200nm with maximum achieved inner rear reflectance >89% and attained absorption in absorber layer from 80% to 90%. The electromagnetic field propagation, reflection and transmission are calculated by using 2D Maxwell’s and Fresnel equations discretised by Finite Element Method (FEM). Different configurations, with plane back reflector/textured dielectric-metal reflector, varied dielectric material/back metal reflector material/texture profile are investigated and reported to attain best structure configuration. Improved light trapping in the absorber layer, increase in rear reflection angle (rr(θ)) and photon absorption are accomplished under standard solar irradiation spectrum AM1.5 conditions. The proposed design would have significant impact in promoting optimum solar cell layer assembly with high light trapping response in a wide variety of silicon thin film solar cells.
- graphene based silicon thin film solar cells
- light trapping
- Finite Element Method (FEM)