Plasmonic-enhanced Si Schottky barrier solar cells

By introducing silver nanoparticles (NPs) and SiO2 spacer layers on top of Si-based Schottky barrier solar cells, we demonstrated a positive and tunable light trapping effect introduced by metallic NPs. A redshift of the surface plasmon resonant wavelength of Ag NPs from 550 nm to 650 nm, corresponding to the optical absorption peak of the solar cell, was observed with an increased average particle diameter from 19.7 nm to 85 nm. Enhanced light trapping effects at distinct resonance wavelengths were observed in the optical spectra of the plasmonic-enhanced devices. Electrical measurements confirmed the expected photocurrent improvement at these corresponding wavelengths. It was also revealed that the Ag NPs enhance the carrier generation rate inside of the Si active layer without sacrificing carrier collection efficiency of the device. The short-circuit current density of the best cell we obtained in this work was improved from 13.7 mA/cm2 to 19.7 mA/cm2, with an enhancement factor of 43.7%. © 2013 Elsevier B.V.