Enhancing light absorption in amorphous silicon thin-film solar cells using composite metal nanoparticles

This study investigates the enhancement of light absorption in amorphous silicon thin-film solar cells by employing metal nanoparticles, combining both experimental fabrication and numerical simulations. Using a rapid annealing process, gold (Au) and silver (Ag) nanoparticles were formed, showing absorption peaks at 600 nm and 450 nm, respectively. In contrast, titanium (Ti), nickel (Ni), and aluminum (Al) did not form nanoparticles, but developed wrinkled surface morphologies, as observed by scanning electron microscopy. Composite structures of Au and Ag nanoparticles achieved broadband light absorption without distinct resonance peaks, a synergistic effect not reported in single-metal systems, with the Ag/Au structure showing better performance than Au/Ag. Multiphysics simulations revealed that incorporating Ag/Au composite nanoparticles into amorphous silicon thin-film solar cells could increase short-circuit current by 1.6 times, and Au/Ag structures by 1.5 times. This approach provides an efficient, dual-metal strategy to overcome the narrow spectral response of single nanoparticles and advance renewable energy applications.