Mitsubishi Materials develops electrode ink for thin-film silicon solar cells

Mitsubishi Materials has developed Ag (silver) nano-ink, ITO (indium tin oxide) nano-ink and SiO2 ink for thin-film silicon solar cell electrodes. These inks are made by dispersing nanoparticles in the ink. When applied to the Si layer of a thin-film silicon solar cell, a sub-micron-thick film called a back electrode can be formed. Its photoelectric conversion efficiency is comparable to that of the original vacuum film formation.

The advantages of thin-film silicon solar cells include: the amount of silicon used can be reduced to about 1/100 of that of crystalline silicon, the energy payback period (the operating time required for the generated electricity to reach the electricity required to manufacture the product) is short, and compared with compound semiconductor solar cells, it is not easily restricted by the amount of raw materials such as Te (tellurium), etc. However, for solar cell manufacturers, the high initial investment cost of introducing various vacuum film-forming devices is a big problem, and it is necessary to significantly reduce costs by converting to a coating film-forming process.

According to reports, the electrode ink can be stably formed on a large piece of glass of 1.4m×1.1m using the coating device "Linearcoater" of Dainippon Screen Manufacturing (DNS). This is conducive to reducing the manufacturing cost of thin-film silicon solar cells.

Mitsubishi Materials will announce the development results at the "21st International Photovoltaic Science and Engineering Conference (PVSEC-21)" held in Fukuoka City, Fukuoka Prefecture from November 28 to December 2, 2011. In addition, Dainippon Screen Manufacturing (DNS) will introduce the coating process of this ink at the "PV China 2011" held in Shanghai, China from November 28 to November 30, 2011.