Broadband Absorption Enhancement in μc-Si:H Thin-Film Solar Cells Based on Silver Nanoparticle Arrays

Abstract

The thin-film solar cell structure with a broadband absorption enhancement is reported. We designed spherical silver (Ag) nanoparticle arrays on or embedded partially into indium tin oxide (ITO) layer of the hydrogenated microcrystalline silicon ([Formula: see text]c-Si:H) thin-film solar cells. The geometrical parameters, such as nanoparticle radius ([Formula: see text], array period ([Formula: see text] and ITO layer thickness ([Formula: see text] are optimized by using the finite element method (FEM). The numerical results show that the key parameter that influences the integrated absorption is period/radius ratio ([Formula: see text]/[Formula: see text] for Ag nanoparticle arrays. Embedding nanoparticle arrays partially into ITO layer with the appropriate thickness can improve broadband light-trapping. The optimized structure shows 50.1% enhancement in the integrated absorption compared to the reference cell when [Formula: see text][Formula: see text]nm, [Formula: see text][Formula: see text]nm and [Formula: see text][Formula: see text]nm. Furthermore, physical mechanisms of absorption enhancement in different wavelength range are discussed according to the electrical field amplitude distributions in the solar cells.