IBM Solar Cell Semiconductors Set World Record
In another one of its technological breakthroughs, IBM Research has set a world record for photovoltaic energy conversion.
An article on the IBM Research blog, written by IBM Research photovoltaic (PV) scientists Teodor Todorov and David Mitzi, describes how IBM's Materials Science team has partnered with Solar Frontier, Tokyo Ohka Kogyo (TOK) and DelSolar to develop an efficient and affordable PV cell made of abundant natural materials.
Photovoltaics is the direct conversion of light into electricity. And photovoltaic systems use solar panels to convert sunlight into electricity.
"So far, the tests of our Cu2ZnSn(S,Se)4 (made of readily available copper, zinc, and tin, and referred to as CZTS) thin-film devices have achieved a world-record PV solar-to-electric power conversion efficiency of 11.1 percent (10 percent better than any previous reports) for this class of semiconductors," the IBM researchers wrote. "And it can be manufactured by simple ink-based techniques such as printing or casting."
IBM said energy from the sun reaching the earth's surface amounts to several thousand times the global consumption of electricity. Yet electricity from PV solar cells currently contributes significantly less than 1 percent of worldwide production. Of the numerous existing PV technologies, none so far have combined the virtues of being highly efficient, cheaply scalable and made with abundantly available materials, IBM said.
Moreover, the most widespread PV semiconductors, made of crystalline silicon, are abundant and highly efficient, IBM's researchers said. "They're in panels used for everything from home electricity to the International Space Station," they said. "However, they have extremely high material purity requirements (>99.9999 percent!), and the wafers are typically cut from large solid ingots and wired in series to form PV modules â making it expensive and difficult to upscale."
In an article in Advanced Energy Materials, IBM's researchers said, "To fabricate the needed photovoltaic module capacity beyond terawatt levels, it is critical to develop low-cost high-throughput production technologies that are unlimited by materials supply and that yield competitive efficiency levels."
IBM said its CZTS PV cells could potentially yield up to 500 gigawatts per year-getting closer to the terawatt levels of renewable electricity the planet needs.
The hope is that within several years this new class of photovoltaic materials will begin to contribute to the wider availability of lower-cost solar electricity, IBM said.