Transparent conducting oxide (TCO) films are optically transparent and offers good electrical conductivity. They have wide range of applications in current electronic market. Currently, ITO and FTO coated glass are widely accepted TCO and are being used in number of electronic devices like LCD, Mobile touch screens, Photovoltaics, OLED, photoelectrochemical and many other applications. ITO and FTO films not only offers high conductivity and optical transparency but their electrical conductivity can also be varied according to application by changing thickness of the film. Although on increasing thickness conductivity increases but transparency reduces, so there is a trade of between transparency and conductivity. ITO and FTO films are easily deposited using PVD techniques on a glass.
Glass Thickness | Sheet Resistance | ITO film Thickness | Optical Transmittance |
---|---|---|---|
1.1mm, 0.7mm, 0.55mm | 4~5 ohm/sq | 260nm | >83% |
1.1mm, 0.7mm, 0.55mm | 6~8 ohm/sq | 185nm | >84% |
1.1mm, 0.7mm, 0.55mm | 10~15 ohm/sq | 135nm | >86% |
1.1mm, 0.7mm, 0.55mm | 15~20 ohm/sq | 95nm | >85% |
1.1mm, 0.7mm, 0.55mm | 20~30 ohm/sq | 65nm | >80% |
1.1mm, 0.7mm, 0.55mm | 30~40 ohm/sq | 50nm | >82% |
1.1mm, 0.7mm, 0.55mm | 40~60 ohm/sq | 35nm | >85% |
1.1mm, 0.7mm, 0.55mm | 60~80 ohm/sq | 30nm | >86% |
1.1mm, 0.7mm, 0.55mm | 80~100 ohm/sq | 23nm | >87% |
1.1mm, 0.7mm, 0.55mm | 300~500 ohm/sq | 13nm | >88% |
ITO coated glass have a barrier layer of thickness 25 nm approx between ITO film and the glass substrate. This passivation layer prevents the Sodium ions in the glass substrate to diffuse into ITO film.
FTO coated glass is preffered over ITO for high temperature applications. FTO can withstand the temperature of 600 °C without being damaged. Not only thermally stable than ITO, FTO shows almost no change in its sheet resistance upto 450 °C temperature. FTO glass appears slightly milky and compared to ITO have slightly lower transmittance in visible region. Also during multi layer thin film device manufacturing, Indium in ITO diffuses into the layers of the top deposited materials resulting Indium as an impurity in a device, thus making device unstable. On the other hand FTO is stable so there is no chance of diffusion. FTO is more mature TCO currently in market than ITO.
Sheet Resistance | Optical Transmittance |
---|---|
<7 ohm/sq (6.0-6.7 ohm/sq) | >77% |
<10 ohm/sq (7.6-8.7 ohm/sq) | >83% |
<15 ohm/sq (12.5-14ohm/sq) | >85% |
<17 ohm/sq (13-16 ohm/sq) | >85% |
30-40 ohm/sq | >85% |
<15 ohm/sq (10-15 ohm/sq) | >85% |
Indium Tin Oxide Coated PET (ITO) (200 mm x 300 mm), SR ~ 9-11 Ohm/s is also available in stock.