Varian using DOE SunShot grant to develop interdigitated backside contact for solar cell fab - Photovoltaics World
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Varian using DOE SunShot grant to develop interdigitated backside contact for solar cell fab

February 9, 2011 -- Varian Semiconductor Equipment Associates Inc. (Varian, NASDAQ: VSEA) secured a $4.8 million grant from the Department of Energy (DOE) under the Obama administration's"SunShot" program to develop U.S. solar technologies. The goal of this project is to reduce the cost of manufacturing interdigitated back contact cells.

Traditional solar cells have metal collectors on the front surface, which block a portion of sunlight. Interdigitated backside contact (IBC) solar cells use metallic conductors on the back of the cell to collect the electricity generated by sunlight, which strikes the fully exposed frontside of the cell.

IBC solar cells create more power per unit area because of their higher efficiency. These higher efficiency cells lower the module cost and the balance of system (BOS) costs for the same power requirement, says VSEA. Also, higher efficiency solar cells increase the amount of power that can be generated within a fixed footprint, such as a rooftop installation.

Using traditional manufacturing processes, IBC cells are more expensive to manufacture than PV cells with frontside contacts. The higher cost of IBC cells, using traditional manufacturing processes, has slowed their implementation. Varian's proposed ion implant process enables cell makers to significantly reduce the cost of IBC cell manufacturing by reducing the number of process steps by 30 to 40%. This ion implant process will also reduce manufacturing variability, cell handling, cell breakage and manufacturing cycle time while increasing yield. IBC solar cells manufactured with ion implant will have much higher efficiencies and will cost per watt than today's frontside contact technology.

Dr. Paul Sullivan, Varian VP of business development, stated, "We are pleased to be the recipient of this SunShot grant and to receive the only award focused on silicon cell technology and manufacturing. This award will support our development of technology to enable the manufacture of advanced high efficiency IBC cell structures with dramatically simplified processes that will ultimately enable the lowest manufacturing costs of solar panels."

Varian has pioneered the use of ion implant in cell manufacture. Solar revenues for 2011 are currently projected to be in the $20-30 million range with strong upside potential. Varian's lead customer, Georgia-based Suniva, has manufactured 19% efficiency solar cells using implant.

Varian will have a booth at the upcoming 5th annual SNEC solar tradeshow in Shanghai, China. In conjunction with SNEC, Varian will present its third vTech Solar technical seminar at the Kerry Pudong Hotel in Shanghai.

Varian Semiconductor Equipment Associates (VSEA) supplies ion implant equipment to semiconductor manufacturers. More information can be found on Varian Semiconductor's website at

More SunShot news:
DOE pursues SunShot initiative
US SunShot initiative participants at PHOTON's Solar Terawatt-Hours Conference Series 
GSLO: Dept. of Energy aims to slash solar costs by 75%
Massachusetts will receive $12.6 million to develop advanced solar energy technologies
HyperSolar supports White House "Sun Shot" initiative to reach grid parity

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