Dual-band absorption of a GaAs thin-film solar cell using a bilayer nano-antenna structure

The paper presents a dual-band plasmonic solar cell. The proposed unit structure gathers two layers, each layer consists of a silver nanoparticle deposited on a GaAs substrate and covered with an ITO layer, It reveals two discrete absorption bands in the infra-red part of the solar spectrum. Nanoparticle structures have been used for light-trapping to increase the absorption of plasmonic solar cells. By proper engineering of these structures, resonance frequencies and absorption coefficients can be controlled as it will be elucidated. The simulation results are achieved using CST Microwave Studio through the finite element method. The results indicate that this proposed dual-band plasmonic solar cell exhibits an absorption bandwidth, defined as the full width at half maximum, reaches 71 nm. Moreover, It can be noticed that by controlling the nanoparticle height above the GaAs substrate, the absorption peak can be increased to reach 0.77.