Article ID | Journal | Published Year | Pages | File Type |
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78721 | Solar Energy Materials and Solar Cells | 2011 | 6 Pages |
Passivation plays a critical role in silicon photovoltaics, yet how a passivation layer affects the optical characteristics of nano-patterned surfaces has rarely been discussed. In this paper, we demonstrate conical-frustum nanostructures fabricated on silicon solar cells using polystyrene colloidal lithography with various silicon–nitride (SiNx) passivation thicknesses. The omnidirectional and broadband antireflective characteristics were determined by utilizing angle-resolved reflectance spectroscopy. The conical-frustum arrays with a height of 550 nm and a SiNx thickness of 80 nm effectively suppressed the Fresnel reflection in the wavelength range from 400 to 1000 nm, up to an incidence angle of 60°. As a result, the power conversion efficiency achieved was 13.39%, which showed a 9.13% enhancement compared to that of a conventional KOH-textured silicon cell. The external quantum efficiency measurements confirmed that the photocurrent was mostly contributed by the increased optical absorption in the near-infrared. The angular cell efficiencies were estimated and showed improvements over large angles of incidence.
Graphical abstractConical-frustum silicon nanorod arrays passivated with 80 nm-thick silicon nitride enhance cell efficiency up to an angle of incidence of 60° via omnidirectional antireflection.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Si solar cells with passivated nano-conical-frustums outperform the conventional. ► Fabrication enabled by scalable polystyrene colloidal lithography. ► Angle-resolved reflectance confirms omnidirectional and broadband antireflection. ► Enhanced quantum efficiency due to increased optical absorption in the near-infrared. ► Improved power conversion efficiency over large angles of incidence.