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.
Absorption enhancement in thin film solar cells with bilayer silver nanoparticle arrays