Reducing light reflection of CIGS solar cells with SiO2 sandwiched by a metal nanoparticle structure

Abstract

In this article, anti-reflection coatings (ARCs) with double-layer metal nanoparticles for Cu(In, Ga)Se2 (CIGS) solar cells were proposed. A study of three ARCs nanostructures (Ag-SiO2-Ag, Au-SiO2-Au and Au-SiO2-Ag structures) on CIGS solar cells was presented using the finite-difference time-domain method. Various ARC nanostructures with different metals (Au and Ag), metal nanoparticle radius, spacing layer (SiO2) thickness, and period (corresponding to the particle density) on CIGS solar cells were optimized in detail. The Au-SiO2-Ag structure was demonstrated to have a better anti-reflection ability when the thickness of the SiO2 layer is 45 nm, the radius of the metal particle is 14 nm, and the side length of the period is 41 nm. The results demonstrated that the reflectivity of the CIGS solar cells with the optimal ARCs structure was reduce by 83% compared with the case of no ARCs. And compared with the MgF2 anti-reflection film, the reflectivity was reduced by 37%.