OSAKA--Panasonic Corp.'s (6752.TO, PC) prototype solar cell has achieved the world's highest conversion efficiency at 24.7%, according to tests performed by the National Institute of Advanced Industrial Science and Technology, the Nikkei reports in its Feb. 11 edition.

It beat the previous record of 24.2% held by U.S. company SunPower Corp. SPWR, -2.99% , a mark that is still recognized as the world's highest by Progress in Photovoltaics, an internationally recognized publication in the field of solar-energy research.