Optical Management by Localized Surface Plasmon of Metal Nanoparticle Film and Application to a Multi-junction Solar Cell

For current-matching of multi-junction Si solar cells, localized surface plasmons (LSPs) of metal nanoparticles (MNPs) are considered as a new solution because MNPs can reflect or transmit light of specific wavelengths. To predict the LSP effect of MNP films in solar cells, we fabricated gold and silver nanoparticle films by spin-coating onto amorphous Si (a-Si) layer and investigated the optical properties of each film. Gold and silver nanoparticle films have the reflection peaks at 700 nm and 600 nm, respectively. Furthermore, we fabricated films by ink-jet printing to adjust the micro and nano-ordered structure and investigated the correlation between the morphology of the films and the optical properties. MNP films fabricated by ink-jet printing have a more balanced reflection and absorption effect compared to films fabricated by spin-coating. Furthermore, we considered appropriate application in multi-junction solar cells using our measured characteristics of the MNP films.