What are transparent conductors?
Transparent conductors, by definition electrically conductive, are thin films prepared from several doped metal oxides. The main components in many items including portable and at home electronics are driven by transparent conductive films (TCF) used in optoelectronics, such as touch screens.
What are Transparent Conductors used for?
“There’s a huge drive in industry to create things that are transparent, inexpensive, conduct well and are made from abundant materials,”
-Mannsfeld professor at the Dresden University of Technology
Transparent Conducting Oxides (TCO’s) have several uses:
- Energy conserving windows– Due to their ability to reflect thermal infrared heat, TCOs are very useful components in energy conserving windows which conserve heat whilst remain safe to touch on the outside. An example would be those used on oven doors.
- Solar cells and flat panel displays– Their electrical conductivity is used in front-surface electrodes for solar cells and flat panel displays. For example these are used in vehicles as an electronic current is passed through the Transparent Films in order to defrost the windows.
- Abrasion-resistant coatings- TCOs are used on the covers of optical bar code readers and windows to protect them from graffiti due to their abrasion and acid-resistant properties.
- Smart phones, tablets and TVs– TCOs are used in touch screen displays and are the main cost driver for these devices. Currently Indium Tin Oxide (ITO) is used, but manufacturers are looking for a cheaper alternative which has the same optical transparency, electrical conductivity and ease of fabrication of ITO.
The potential uses, possible set backs the future
As the market for flexible transparent conductors is expanding, scientists and manufacturers are looking for inexpensive, more efficient alternatives to the present materials. Indium Tin Oxide (ITO) is currently used, but it has limitations including:
- Cost– ITO is an expensive and scarce material
- Supply– The earth´s supply of this material is decreasing, whilst the market for transparent conductors is also increasing
- Fragility– ITO is brittle and prone to fracturing, thus causing its conductivity factor to decrease. This limits its use in many emerging technologies which require flexibility.
The material Graphene is sparking a particular interest due to its unique properties. Graphene has several advantages over ITO including its flexibility, robustness, weight, chemical stability and cost. Graphene further has high electronic mobility and is thought to be the high tech material of the 21st century. This exciting new substance has some very useful properties including its ability to bend, stretch and roll whilst still maintaining its other properties. More information on the property and uses of graphene can be found here.
Graphene was also recently a hot topic of interest at the Mobile World Congress on the 25th February 2016, with particular reference to the use of Graphene in the future of the mobile world. In addition, companies have already started to incorporate graphene into their TC technologies such as Fujitsu and Eikos Inc.
The issue now with graphene is finding a scalable and inexpensive method of producing it. This is work in progress and several new technologies are emerging onto the market to provide low cost methods of doing this such as this tech for transfer listing. If scalable, low cost graphene production methods can make it to market, it provides an exciting scope for the expansion and development of new technologies and devices.
Conclusion
To conclude, transparent conductors are highly useful components in many electrical items and devices and in the optoelectronic sector, however the current materials used are expensive, unsustainable and limiting. The market for transparent conductors is expanding, pushing the need to find a more cost-effective, sustainable alternative. Graphene, the new material of interest, provides a solution to help meet this market need. It comes with production limitations, but emerging new low-cost methods of production are providing promise for the future.
At Photon Transfer we provide an open innovation marketplace for new technologies trying to make it to market; including alternative methods of graphene production. Our current technology for transfer listings can be found here.
Alternatively check out our website to find out how we help bridge the gap between science and market: http://photontransfer.com/