Sony has been involved in developing technology for dye-sensitized solar cells for several years. Dye-sensitized solar cells are next-generation solar cells based on innovative technology. Unlike conventional silicon-based solar cells, dye-sensitized solar cells consist primarily of photosensitive dye and other substances. Dye-sensitized solar cells are able to generate electricity by converting energy from light absorbed by the dye.
Since these solar cells can be produced from low-cost materials using simple manufacturing processes (such as coating and printing), overall manufacturing expenditures are expected to be comparatively low.
Other advantages over silicon-based solar cells include the ability to use a variety of designs and colors and achieve high performance under indoor and low light settings. In addition, changes in the angle at which light hits the surface of the cells have minimal effect on performance. Such dye-sensitized solar cell advantages are expected to expand the range of use for solar cells, which are ideal for a variety of consumer-related applications in which conventional solar cells are unsuitable.
A dye-sensitized solar cell consists of an electrolyte sandwiched between a photoelectrode and a catalytic-electrode (counter electrode). The photoelectrode in this case, is a conductive glass plate coated with porous titanium dioxide to create a layer which can adsorb photosensitive dye molecules. Light energy absorbed in the dye is converted to electricity via solar cell electrochemical properties.
In nature, light absorbed by pigment molecules is converted into a different form of energy through photosynthesis. Photosynthesis occurs when chloroplast pigments in leaves convert light energy into chemical energy, which is then used to produce carbohydrates. Because dye-sensitized solar cells also extract electrical energy from light absorbed by pigment molecules (dye), they are also known as "pseudo-photosynthetic solar cells."
Sony commenced R&D in this field in 2001. In April 2009, a prototype module based on Sony's unique "Concerto Effect" dye-mixing technology set a world record for a dye-sensitized solar cell by achieving energy conversion efficiency of 8.4%. Aiming to launch commercial products in the near future, Sony has accelerated efforts to enhance the photovoltaic (light to electric energy conversion) efficiency and reliability of these cells and develop effective manufacturing processes.