“There’s a potential shift in the market,” says Vikram Singh, general manager for the photovoltaic division at GT Advanced Technologies. He says some western companies could become more competitive because they have technologies to take advantage of the materials.
Several other companies are developing technologies similar to Monocast, including solar-panel makers in China, such as Suntech and the Dutch equipment maker ALD.
The HiCz technology can be considered the next step on the way to higher-efficiency solar cells. It can be used to make monocrystalline silicon, even the phosphorous-doped type, for about the same cost as the Monocast technology. HiCz could allow a leap from cells that convert 16 to 18 percent of the energy in sunlight into electricity to ones that can convert 22 to 24 percent, thus decreasing the cost per watt of solar power. But it can’t be retrofitted to existing equipment, which could slow its adoption.
The conventional way to make monocrystalline silicon is to introduce a seed crystal into a pool of molten silicon and slowly draw it out—as you do, it forms a large tube-shaped chunk of silicon called a boule, in which all of the atoms are lined up in the same orientation. This is usually done in a batch process, but the HiCz process makes it possible to continuously feed in raw silicon to the melt, along with whatever trace elements are needed to give it the desired electronic properties. The continuous process is more productive, which means fewer machines are needed, reducing costs. It also produces high yields when introducing materials including trace elements such as gallium and phosphorous. GT estimates the process can reduce the costs of making monocrystalline solar by between 20 and 40 percent.