1366 Technologies

1366 Technologies has developed a new process for making highly efficient silicon wafers, which typically account for almost 40% of the cost of a solar module. The process cuts the cost of wafer manufacturing by more than 50% and reduces the energy required by more than 60% when compared to traditional silicon ingot sawing techniques that are now used in about 90% of wafer production. The wafers are very similar to traditional wafer cells and can be used in more than 80% of solar manufacturing facilities worldwide without the need to install new equipment. In the past year, 1366 has made significant improvements to its cell efficiency and has delivered on its first commercial installation – a 500KW installation in Japan.

The company takes the protection of its intellectual property seriously. It has more than 60 issued and pending patent applications, including one for "Method and Apparatus of Making Thin Semiconductor Sheets from Molten Material.”

Traditional wafer manufacturing involves melting down silicon into large blocks of crystalline silicon (ingots), which are then cut into bricks, polished and sliced into wafers. The slicing is particularly wasteful, with much of the raw material ground into dust. As much as half the silicon is wasted in addition to kilometres of diamond-edged cutting wire per block. The stages of this process are shown in Figure 1 below.

In contrast, 1366’s "Direct Wafer" process melts the top layer of silicon, then uses laser sensors to cool the layer, creating a hardened top piece that is then removed and cut to size to form the final wafer. Leftover trimmings are recycled back into the melting process. This process uses less energy and wastes less silicon, according to the company. BNEF has drawn up the diagram in Figure 2 based on what can be understood to be the company’s manufacturing process, as found in its 2014 patent. The process has otherwise not been disclosed.

The molten polysilicon is held to the substrate by vacuum suction during less than 10 seconds of contact. Once the solidification reaches the desired thickness, the substrate is moved away from the melt, with the grown wafer attached. Gas pressure may then be applied to separate the wafer from the substrate, creating the final solar wafer in less than 10 seconds. (This process is deduced from the 1366 patent and hasn't been confirmed by the company).