Sanyo Electric Co Ltd reduced the thickness of its HIT (heterojunction with intrinsic thin layer) solar cell to 85μm, less than half that of its previous model, and yet achieved a high conversion efficiency of 21.4% with a cell measuring about 10 x 10cm (103.3cm2).
Sanyo announced the achievement at the JSAP (Japan Society of Applied Physics) 56th Spring Meeting, 2009, which is taking place at Tsukuba University from March 30 to April 2, 2009. The company made the same announcement at the 23rd EU PVSEC in Spain in September 2008.
Slimmer cells lead to lower costs of silicon materials. If the company can realize this high efficiency and low cost at the same time for production models, the competitiveness of its HIT solar cells will probably increase significantly.
The new HIT solar cell features an open voltage as high as 739mV. Its short-circuit current is 37.3mA/cm2, and its form factor (FF) is 0.776.
Sanyo has already developed an HIT solar cell with a conversion efficiency of 22.3%. However, it is as thick as 200μm. Despite the large reduction in the thickness, the new solar cell maintained a conversion efficiency almost as high as that of the previous model, while raising the open voltage from the previous 725mA/cm2.