When a thin film electronics technology needs an anode, inevitably developers reach for ITO. Since ITOs properties are so well understood it is no wonder that ITO achieves such reliable conductivities and transparencies. It is good be reminded where this miracle material came from and how much time and effort went into developing it. ITO has been around since the 1970’s as a transparent conductor. However, as reported by John Fenn Jr. in a 2004 article on ITO development in the Society of Vacuum Coaters, ITO was not nearly as transparent or conductive as it is today. Most of the improvements in ITO technology were market pull as many ITO customers wanted better and better films. In 1988, as recalled in the article, ITO broke what was at that time, the standard transparency of 88% to 92% by a developed understanding of a technology professional.
We all know that ITO use is somewhat of an Achilles’ heel for emerging markets, based on supply and availability concerns. Organic transparent conductors (CNTs, graphene, polymers) are indeed all the rage because flexible is where the market believes the future will go. But there are so many opportunities in non-flexible or mildly bendable spaces, that we wonder why anyone would want to use ITO in these spaces at all? Many alternative transparent conducting oxides, including some old names, like FTO and AZO, are being developed to match the characteristics of ITO. We are probably at a cusp of a technology change for alt-TCOs like we were for ITO 20 years ago. Engineering the alt-TCOs are providing materials users with more choices for TCs, and from more accessible materials. If end users demand improvements in the alt-TCOs, they can be realized.
BIPV makers, especially in the emerging DSC technologies are investing in FTO technology. Smart windows and touch screen still using ITO? This could be a danger as alt-TCOs already match the anode characteristics needed for these products, and with the case of touch screen, Asian companies are already adapting these products. Stick with ITO and be prepared for price fluctuations and instability of supply, or champion the alt-TCO technology and reap the rewards. These concerns are discussed in our new report Emerging Markets for Non-ITO Transparent Conductive Oxides, available now from NanoMarkets.