Boeing's Spectrolab subsidiary said it has begun volume production of its newest terrestrial triple-junction III-V-based solar cell, the C3MJ+. The device has an average conversion efficiency of 39.2%, which the company claims makes it the most-efficient cell on the market.

The new cells improve on the 38.5%-efficient C3MJ cells that have been in production since mid-2009 at the company's fabrication facility in Sylmar, CA, near Los Angeles.

Delivery of the first C3MJ+ cells is planned for January 2011.

"These more efficient cells are drawing interest from a number of current and potential customers," said Russ Jones, Spectrolab director of CPV business development. "Last year we set a new world record for efficiency with a test cell that peaked at 41.6%. We now have entered production with essentially this same technology and plan to deliver the first of these 39.2% efficiency cells in January."

"Given the new cells' close similarity to our existing production cells, we believe that our current C3MJ customers will be able to easily upgrade for more efficiency," he added.

Spectrolab, which is the leading supplier of multijunction photovoltaic solar cells, said it expects to achieve a 40% average production efficiency for terrestrial solar cells in 2011.

The company's cell customers in the concentrating photovoltaics sector include SolFocus, Amonix, Soliant Energy, and Energy Innovations.