Scientists working in the Rochester R&D Center of Natcore Technology Inc. have produced an all-back-contact silicon "HIT-structure" (heterojunction with intrinsic thin layer) solar cell using their proprietary laser technology.
"Silicon HIT-structure cells have been shown to yield record efficiencies of greater than 25%," says Dr. David Levy, Natcore's Director of Research and Technology. "Natcore's HIT-structure cells are made using thin amorphous silicon layers in combination with a standard crystalline silicon solar wafer. This concept makes very efficient cells, as seen in the Sanyo/Panasonic HIT™ cell."
Natcore's scientists used a laser in applying contacts to the rear of the cell. In addition to further increasing cell efficiency relative to industry standards, the Natcore all-back-contact technique could allow production of these high efficiency cells at low cost.
Panasonic recently reported an all-back-contact HIT-structure with 25.6% conversion efficiency – the highest efficiency ever reached for a silicon solar cell. That cell, however, was produced using a relatively complicated, higher-cost process. Natcore believes that it can achieve similar efficiencies at a much lower cost and without the environmental damage incurred through the chemicals and energy required for the high-temperature process.
Because of their initial results, Natcore has moved to protect its new process by filing a provisional patent application titled with the United States Patent and Trademark Office.
"Basic HIT-structure cell technology is a couple of decades old," says Chuck Provini, Natcore President and CEO. "But our HIT-structure cell is not your father's HIT cell. We've made a device that has all of the positive aspects of a HIT cell, but also with our laser technology that will allow us to significantly streamline production. Our cell will have a much lower manufacturing cost than the cells made using the older technology. We continue to change the ways solar cells are made."