Last year, South Korea’s Qcells set the world record for large-area silicon solar cell efficiency, a development that promised to dramatically shrink the size of solar projects and slash costs. Qcells, a subsidiary of South Korea’s giant conglomerate Hanwha Corp, set the world record after achieving 28.6% efficiency by combining a top light-absorbing layer of perovskite with a bottom silicon layer to capture a broader spectrum of sunlight. For some context, high-end commercial solar panels typically operate at 21% to 23% efficiency,…