Enhanced photocurrent in evaporated solid-phase-crystallised poly-Si thin-film solar cells using rear surface plasmons

We demonstrate enhancements in photocurrent and conversion efficiency for thin-film Si cells on glass due to plasmonic light-trapping. In this work, silver nanoparticles were formed on the rear surface of evaporated solid-phase-crystallised poly-Si thin-film solar cells coated with an intermediate dielectric layer. We find that localised surface plasmon excited in nanoparticles can increase the light absorption of the Si films and thereby enhance the spectral response and efficiency of the cells. Short-circuit current and efficiency under standard illumination condition increased by 13% and 10% respectively compared to the same cell without surface plasmons. This is a very important finding as evaporated Si thin-film solar cells have few options for effective light trapping which are simple and do not harm the cell structure, like surface plasmons. Effects of different dielectric layers on enhancement are also investigated.