SOLAR TODAY March 4, 2013
The Japanese news service Nikkei reports that Panasonic has demonstrated a prototype solar cell with a conversion efficiency of 24.7 percent, in tests performed by the National Institute of Advanced Industrial Science and Technology. This exceeds the previous record of 24.2 percent held by SunPower. Panasonic purchased Sanyo in 2010, including Sanyo’s HIT solar technology. The company says the efficiency improvement comes from a more transparent surface membrane and better electrodes. Panasonic plans to commercialize the prototype to improve the conversion efficiency of its mass-market solar cells, now 21.6 percent. The company has opened a factory in Malaysia, with an initial annual capacity of 300 megawatts (MW), and expects to reduce production costs by 20 percent.
In Switzerland, the École Polytechnique Fédéral de Lausanne (EPFL) reports that its Institute of Microengineering has achieved a record 10.7 percent efficiency in a single-junction microcrystalline silicon thin-film solar cell, clearly surpassing the previous world record of 10.1 percent set by the Japanese Kaneka Corp. in 1998. The record performance, certified by the Fraunhofer Institute, was achieved in a silicon layer 1.8 micrometers thick, compared to a typical crystalline wafer of about 180 micrometers. The team was led by Dr. Fanny Meillaud and Dr. Matthieu Despeisse. By using 99 percent less material, the group aims to bring thin-film production costs down near €35 per square meter, matching the price of standard roof tiles.
Because one microcrystalline silicon junction is normally combined with an amorphous silicon junction for a broader use of the solar spectrum, the new record suggests strongly that a multi-junction device may achieve more than 13.5 percent conversion.
The work is supported by the Swiss Federal Office of Energy (SFOE), the EU-FP7 program, the Swiss National Science Foundation and the Commission for Technology and Innovation. (EPFL report by Emannuel Barraud).