One final week of chats with the ITO cognoscenti. "What do they make of all those ITO replacements?" It turns out that they all believe that none of the current ITO replacements work well yet in terms of transparency or conductivity. Or both. Even the companies that make ITO replacements seem to agree on that! And they don't agree on much else! One interviewee tells me "ITO on glass is unbeatable." And he's the guy selling an ITO substitute!

Makes you wonder why he's bothering.

The answer to this question seems to be that there are already some niches where an ITO substitute makes sense for particular reasons. The two that are mentioned most frequently are electrostatic coatings and touch screen displays. In both instances, the share of value represented by ITO is quite big; 20 percent for a touch screen I am told. High Indium prices matter in these ITO intensive markets. For some large LCD displays, that proportion is just 5 percent, so Indium prices matter less.

The touch screen displays raises another issue though. They wear out pretty quickly. You can see this in your PDA if you keep it too long. You can see it much more dramatically in the conductor failure that makes you have to stab or punch the displays at checkouts rather than gently touch them. Could the ITO replacements do a better job? The answer seems a bit indefinite right now. But many of the materials firms I have talked with think they will.

I am not quite sure how many touch screen displays there are out there. Clearly, a lot more than flexible displays which is the other place that ITO might claim an advantage. So the humble touch screen, not the sexy flexible display, might be a very good place to start to nibble away at ITO dominance.

But it's just a beginning. When pushed the ITO replacement guys will tell you clearly that they expect to sell their stuff well beyond the touch market. They pin their hopes on improved dispersions and the ability of the newer materials to move beyond sputtering; universally regarded as wasteful and energy intensive. (I suppose that means that the future of TCOs lies in inks and printing.) Indium prices are secondary issue, they say.

And this touch screen thing has me intrigued. Suppose these do start using new TCOs? Would it mean the beginning of the end for ITO? Certainly, not. But perhaps it would mean the beginning a vibrant new market for nanomaterials.