ITO Coated Glass Slides, Sodium Ion Diffusion & the SiO2 Barrier

Diamond Coatings Inc recently introduced a new range of ITO coated glass slides featuring an SiO₂ barrier layer. Here is why.

Soda Lime Float Glass

Produced by drawing glass over tanks of molten tin*, soda lime float (SLF) glass can be produced at relatively low processing cost. This type of glass is subsequently the most commonly used substrate for ITO glass slides and a whole range of other applications, including, among others, bottles & jars for food, beverages and various commodity items; window-panes and, when tempered, glass bakeware.

Typically featuring one side that is flatter/smoother (the side facing upwards, away from the molten tin bath) than the other (the side facing the molten tin), SLF glass can be cut to varying sizes and supplied as standard or chemically and/or thermally toughened.

ITO Coated Glass and Sodium Diffusion

Coating SLF glass slides with a transparent, highly conductive layer of indium tin oxide (In₂O₅Sn) gives these slides the ideal properties for use within an array of medical, research & development and science applications.

Flat SLF glass does, however, contain approximately 14wt% of sodium (NA) in the shape of sodium oxide (Na₂O). Note: wt% denotes weight percentage, so 14wt% basically means 14 per cent of SFL glass’ weight consists of Na₂O.

While this is not a problem as such, it does mean NA ions may diffuse out of the SLF glass and into the indium tin oxide layer. Unless efficiently blocked, this NA diffusion can have a detrimental effect on the ITO layer’s optoelectronic properties & overall performance and can also disrupt the performance of any devices grown on this layer. Silicon oxide inhibits this diffusion of Na ions.

ITO Coated Glass Slides with SiO₂ Barrier

Diamond Coatings’ new ITO glass slides feature a thin (25nm) barrier coating of silicon oxide (SiO₂) between the SLF glass and the ITO layer because by inhibiting sodium ion diffusion, this layer effectively enhances both the quality of our ITO glass slides and their longevity.

Learn More

For more information on our ITO glass slides or other products offered by Diamond Coatings Inc and/or to discuss your scientific, medical or R&D project’s specific requirements, please do not hesitate to give us a call on (480) 999-3456 (or 001 (480) 999-3456 if calling from outside the US), e-mail us: sales@diamondcoatings.com or use our online contact form today.