  Nanoparticle (NP) arrays of noble metals strongly absorb light in the visible
to infrared wavelengths through resonant interactions between the incident
electromagnetic field and the metal's free electron plasma. Such plasmonic
interfaces enhance light absorption and photocurrent in solar cells. We report
a cost effective and scalable room temperature/pressure spin-coating route to
fabricate broadband plasmonic interfaces consisting of silver NPs. The NP
interface yields photocurrent enhancement (PE) in thin film silicon devices by
up to 200% which is significantly greater than previously reported values. For
coatings produced from Ag nanoink containing particles with average diameter of
40 nm, an optimal NP surface coverage of 7% was observed. Scanning electron
microscopy of interface morphologies revealed that for low surface coverage,
particles are well-separated, resulting in broadband PE. At higher surface
coverage, formation of particle strings and clusters caused red-shifting of the
PE peak and a narrower spectral response.
