Sachs expects that new antireflection coatings will further raise multicrystalline cell efficiencies. One of his firm’s future goals will be a switch from expensive silver bus wires to cheaper copper ones. And he has a few ideas regarding how to successfully make the substitution. “Unlike silver, copper poisons the performance of silicon PVs,” Sachs says, “so it will be crucial to include a low-cost diffusion barrier that stops direct contact between copper and the silicon.” In this business, it’s always the little devilish details that count.
Note: This article was originally printed with the title, "Sunny Days for Silicon".