by Timon Singh, 08/25/12
Working together with Solar Frontier, Tokyo Ohka Kogyo (TOK) and DelSolar, IBM’s Materials Science team has developed an efficient and affordable PV cell made of abundant natural materials—and they have broken a world record doing it! The team created a solar semiconductor made from readily available elements such as copper, zinc, and tin (known as CZTSSo), and achieved a PV solar-to-electric power conversion efficiency of 11.1% – that’s 10% better than previous designs using this class of semiconductors.
It is hoped that this breakthrough will herald a cheap and effective way to capture the sun’s energy and power the planet’s electric systems. Currently, most existing PV technologies are either not highly efficient, cheaply scalable or made with abundantly available materials – however that is what IBM aim to change.
By using simple ink-based techniques such as printing or casting, the new method can be easily duplicated, unlike the current way of making PV semiconductors with crystalline silicon. While these are abundant and highly efficient, they have extremely high material purity requirements making them expensive to buy and difficult to upscale. There are other thin-film materials that can be used, such as Cu(In,Ga)(SSe)2(CIGS) and CdTe. While these alternatives are easy to integrate into buildings and consumer products, their compounds do contain rare and expensive elements that can increase cost.
While the team are ecstatic with their record-breaking success, they are not going to stop now. In a statement, the team said “the focus of our joint-development team remains to further increase this device efficiency and transfer the technology to environmentally-friendly, high-throughput industrial manufacturing. 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.”