Cold substrate method to prepare plasmonic Ag nanoparticle: deposition, characterization, application in solar cell

Abstract

In this study, the surface plasmon effects of the Ag nanoparticle were investigated depending on the substrate temperature and coating time. Deposition procedure for the Ag coating was the vacuum deposition at low substrate temperature (< 300 K) instead of the commonly used the vacuum deposition at high substrate temperatures. The Ag thin films were deposited on n-type Si, glass and solar cell with safety glass substrates. The structural and optical characteristics of the Ag thin films prepared on Si and glass substrates were investigated. The Ag thin films had a polycrystalline structure with cubic phase. The (111) preferred orientation for 300 K substrate temperature was changed to (200) after 200 K substrate temperature. Homogeneous nano-sized Ag particles on Si were obtained at the 150–200 K temperature range. Optical measurements were performed for the Ag thin films prepared on glass substrates. According to reflectance measurements, plasmon resonance effect of the Ag nanoparticles was observed around 435–540 nm. The Ag nanoparticles prepared on solar cell at low substrate temperature increased the solar cell efficiency for all coating time because the nanoparticle size and shape were not changed significantly with the coating time. However, the Ag thin films prepared at high substrate temperature decreased device efficiency with the increasing coating time.