A Crystalline Metallic Copper Network Application Film Produced by High-Temperature Atmospheric Sintering

摘要

We show the first production of a copper (Cu) application film (AF) consisting of a novel network of crystalline metallic Cu embedded with copper–phosphorus–oxygen glasses (Cu $_2$(PO$_4)$ and Cu $_2$P$_2$O $_7)$ to provide new feedstock materials for crystalline silicon (Si) photovoltaics (PVs). The Cu crystal network was preferentially grown in AF, and thus, a Cu AF with low-electrical resistivity was formed in air at elevated temperatures of $geq 450 ^{circ}$ C by using a copper–phosphorus (Cu–P) alloy paste as a starting material for the sintering. The Cu–P alloy had the role that governed deoxidization of a cuprous oxide, which was formed on heating during the sintering, by virtue of a concurrent oxidation of the Cu phosphide at elevated temperatures. Our results may open the way to the widespread use of atmospherically sintered Cu AFs for mass-production of next-generation crystalline Si PVs.