Abstract
Improving the light absorption in thin-film solar cell is essential for enhancing efficiency and reducing cost. Here, we propose an ultra-broadband amorphous silicon solar cell based on a periodic array of titanium ring-shaped metasurfaces, which achieves more than 90% absorptance in the visible range of the solar spectrum. The surface plasmon resonance supported by the nanoparticles together with the resonance induced by the metal-insulator-metal Fabry-Perot cavity leads to this broadband absorption. The impact of various materials of functional layers and the geometric structure of the nanoparticle on absorption performance is discussed in detail, and super broadband resonance is achieved after optimization. Moreover, the optimized solar cell is tested for different solar incidence angles and it is found that the structure exhibits high absorption efficiency even at large angles. Thus, the proposed solar cell design may be beneficial for most of the photovoltaic applications.