Evaluation of Ag-coated Cu paste as Ag-saving electrode paste for silicon heterojunction solar cells

Abstract This study evaluates an Ag-saving electrode paste of Ag-coated Cu particles mixed with conventional Ag powder (Ag-coated Cu paste) for silicon heterojunction (SHJ) solar cells. The results show that the Ag-coated Cu paste achieves electrical properties comparable to conventional Ag paste when the blending ratio of Ag powder is 37% or higher. The SHJ solar cells fabricated using the Ag-coated Cu paste exhibit comparable efficiencies to those of SHJ solar cells fabricated using conventional Ag paste while reducing the usage of Ag by approximately 60%. Furthermore, the Ag-coated Cu paste shows superior electrical contact properties with resource-saving Al-doped ZnO compared to conventional Ag paste. The hard X-ray photoelectron spectroscopy analysis reveals that this superiority is attributed to a reduction in contact resistance resulting from optimized band alignment. These results highlight the Ag-coated Cu paste potential as a cost-effective and sustainable solution for next-generation solar technologies.