[RenewableEnergyAccess.com] Efficiency is the name of the development game when it comes to solar cells. SANYO Technology and the Clean Energy Company have been improving upon their heterojunction with intrinsic thin layer (HIT) solar cell, and reported an efficiency level of 21.6 percent for their efforts. This was accomplished through optimization in many areas, including lowering the current collector’s resistance level, improving the aspect ratio, optimizing the design for transparent electrodes, and improving the cell’s junction formation. The resulting efficiency level exceeds 21.3 percent, which until now, was the highest level delivered by SANYO HIT solar cells. The HIT solar cell is 10cm square, nearly the same size as solar cells currently used for home and industrial applications.