A number of countries in the world are proactively introducing solar cells.
A solar cell is a device that converts solar rays into electric power. Its outstanding feature is that it does not emit CO₂ during power generation. In order to popularize solar cells to prevent climate change, it is necessary to develop technologies not only to improve their efficiency, but also to reduce their introduction cost and to increase their durability for long use under severe conditions.
The AGC Group is making combined use of its core technologies, namely in glass, chemicals, and ceramics, to develop technologies to improve the efficiency, durability, and productivity of solar cells and to provide materials for these cells.

Expansion of the solar cell market

The solar cell market has been rapidly expanding in countries such as Germany, Japan, the United States and Spain in recent years.In 2007, solar cells generating a total of approximately 3,500 MW*1 of energy were produced worldwide. This market is expected to increase to approximately 17,000 MW*1 in 2011.

*1 AGC estimate

Scale of solar cell market

*Estimates as of March 2009

Reduction effect in CO₂ emissions due to the expansion of the solar cell market

A shift from thermal power generation to solar cells will lead to a reduction in CO₂ emissions. It is predicted that global CO₂ emissions can be reduced by 11 million tons in 2010 and by 120 million tons in 2020 through the expanded use of solar cells.

Reduction effect in CO₂ emissions through the introduction of solar power generation

*AGC estimate (calculated based on the European Photovoltaic Industry Association's [EPIA's] demand forecast)

Contributing to the Reduction of CO₂ Emissions by Improving the Power Generation Efficiency, Durability, and Productivity of Solar Cells

Solar cells are expected to help reduce CO₂ emissions throughout the world.
The AGC Group is contributing to the higher performance of solar cells through its glass, chemical, and ceramics technologies.
To be specific, in the field of photovoltaic cover glass, we hold the leading share of the world market.

The AGC Group's materials and technologies for solar cells

(1)Transparent conductive oxide (TCO)-coated glass substrate

In thin film silicon solar cells,*2 TCO films function as conductors (electrodes) that derive electrical energy from sunlight. These films must meet the following conditions: they must be able to conduct electricity, they must be transparent, and they must be able to efficiently scatter light by means of their surface concavoconvex texture, to conduct more light into the photovoltaic layer for higher power generation efficiency.

*2 Thin-film silicon solar cells are made by forming very thin silicon films on glass substrates. These cells use only about one-hundredth the amount of silicon compared with typical crystalline silicon solar cells (solar cells made by processing silicon ingots into wafers). On the other hand, thin-film silicon solar cells have lower power generation efficiency (less than 10%) compared with crystalline silicon cells (approx. 15%), which is the challenge for thin-film silicon solar cells.

Thin-film silicon type

Features of the AGC Group's technology

The AGC Group's TCO films have the following characteristics:they are highly conductive films with low electric resistance and scatter light very efficiently. We embarked on the development of TCO films in 1985. Our first product, Type U TCO film became the world's standard for TCO films, but it scattered only 10% of incoming sunlight (haze rate). After releasing the Type VU TCO film, which had a better haze rate, on the market, we unveiled the development of Type HU TCO film, which can scatter up to 90% of incoming sunlight through our original nano-scale (one-billionth of a meter) film forming technology. By generating smaller concavoconvex parts onto the existing concavoconvex surface, we have made it possible for the film to reflect sunlight in a more complex manner in order to conduct more light into the photovoltaic layer for improving the power generation efficiency.
The AGC Group also possesses a technology to coat TCO films onto float glass concurrently at the time the glass is produced. We will continue our development activities to meet the needs of still more customers.

(2)Antireflection coating

We have developed this low reflective technology by applying our unique coating technology. The light transmittance is improved by coating photovoltaic cover glass with this technology, which in turn improves the efficiency of solar cells.

(3)Figured glass (photovoltaic cover glass)

This figured glass scatters light due to the adoption of a unique surface morphology technology and helps increase the light transmission to solar cells, in particular for light of specific wavelengths that can be easily converted to energy.

(4)Fluoropolymer films for front sheets and backing sheets of PV modules

When used as front sheets for photovoltaic(PV) modules, these films help improve the efficiency of solar cells because they transmit most light (around 95%).
When used as backing sheets, they help improve the durability because of their excellent weatherability and they do not deteriorate even if left outdoors for a long time. Their lightness is also a feature which helps reduce the weight of PV modules.

(5)Powder glass

We have developed this product by combining our glass, chemical, and ceramic technologies. It is used for binding silver and aluminum electrodes and contributes to improve their conductivity.

(6)Sputtering targets for TCO films

The sputtering targets are used to make thin films by vacuum sputtering. (In a vacuum chamber, ions hit the target and its components rush out and stick to the board opposite the target.) For example, we use the materials to make TCO films, which are indispensable as front-side electrodes for solar cells.

(7)High purity SiC components for solar cells

These SiC materials have high purity and they are used as a jig in the semiconductor thermal process. During the wafer processing for solar cells, they do not deform even at temperatures of 1,200°C or higher because of their excellent heat resistance and high temperature strength.