Low cost transparent conductors
Silicon doped zinc oxide thin films may be deposited via vacuum or solution phase techniques. They show high conductivity, high transparency and low haze. They are suited to a wide variety of applications.
Researchers at the Universities of Oxford and Birmingham have worked on the optimisation of doped Zinc Oxide (ZnO) based materials. ZnO based materials have been of interest for electronic applications for many years in view of their suitable band gap, electron density and electron mobilities. Until now their exploitation has been limited by their relatively low electrical conductivity.
The latest work in Oxford has addressed the requirement to be able to deposit these materials from the solution phase, negating the need to use vacuum techniques eg pulsed laser deposition and sputtering. Doped ZnO thin films made with our method have shown the following benefits:
high conductivity within an order of magnitude of ITO prepared by a solution phase deposition
greater than 80% optical transparency for comparable film thicknesses
lower cost as ZnO is an abundant material
solution phase process avoids expensive vacuum manufacturing techniques
process suited to large area coverage
variable topography substrates can be accommodated
Today, indium tin oxide (ITO) is the most used transparent conductive oxide (TCO). TCOs are used in a number of areas eg liquid crystal displays, flat panel displays, plasma displays, touch panels, electronic inks, organic light-emitting diodes, solar cells, lighting, touch sensors, antistatic coatings and electromagnetic shielding.
Although, ITO offers an excellent combination of electrical conductivity and optical transparency, it also uses most of the world’s rapidly depleting indium resource, so it is expensive. The cost, performance and processing convenience of these new ZnO based materials offer an opportunity to substitute ITO and also to enable a number of new applications.
This work has been patented.
Oxford University Innovation would like to talk to companies interested in developing the commercial opportunity. Request more information if you would like to discuss this further.
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