Transparent Conductive Oxide (TCO) Film for Thin Film Silicon Photovoltaic Devices

Films that Scatter Sunlight with a Nanoscale Concavoconvex Surface for Improved Power Generation Efficiency

What is a TCO Film?

In thin film silicon photovoltaic devices, (Note 1) 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.

  • (Note 1) Thin-film silicon photovoltaic devices are made by forming very thin silicon films on glass substrates.

Thin film silicon photovoltaic devices

Thin film silicon photovoltaic devices

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. While Type U TCO film which we developed as the first product became a global standard, a light scattering property was limited to only short wavelengths. After releasing the Type VU TCO film, which was improved, on the market, we unveiled the development of Type HU TCO film whose light scattering property is improved to near infrared rays which has longer wavelengths 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. This, in turn, increases the effect of confining light with longer wavelengths, and as a result more light can be supplied to the photovoltaic layer to improve the power generation efficiency.

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.

Thin-film silicon type

Thin-film silicon type

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