Transparent metal helps reduce smartphone screen prices

American scientists have developed a new form of transparent metal that conducts electricity well, allowing the production of smartphone and TV screens at a cost of only 5% of current technology.

Transparent metal will help make phone screen production cheaper. Illustration: cfn.

The problem with these displays is that they rely on indium tin oxide (ITO), according to New Science. More than 90% of displays on the market rely entirely on this expensive material. Over the past 10 years, the price of ITO has fluctuated, from $200/kg in 2004 to more than $1,000/kg in 2006, then back down to around $400-$750/kg in recent years.

ITO currently accounts for 40% of the cost of a smartphone or tablet, while memory chip and processor prices continue to fall. Continued use of the material in display manufacturing will slow the development of bigger and better technologies.

In a December 14 publication in the journal Nature Materials, scientists at the University of Pennsylvania, USA, successfully researched a new material containing bonded metals that can replace ITO while still ensuring optical transmittance, electrical conductivity, and manufacturing efficiency.

The team, led by engineer Roman Engel-Herbert, developed a 10nm thin film of bonded metal with a unique molecular structure. While in most metals such as gold, silver, copper and aluminum, electrons move like a gas cloud, in bonded metal electrons move like a liquid. This property allows the material to change phase depending on how it is used.

"We are trying to make bonded metals transparent by changing the effective mass of the electrons," says Engel-Herbert. "This is done by choosing materials in which the electrostatic interaction between negatively charged electrons is very large compared to their kinetic energy. In this condition, the electrons 'feel' each other and behave like a liquid rather than a gas of non-interacting particles."

“When you shine light on this material, it reflects less, and it becomes more transparent,” Engel-Herbert explains. At the same time, the material's electrical conductivity does not change when it changes phase under the influence of light.

According to the researchers, they can produce binding metals such as strontium vanadate and calcium vanadate much cheaper than ITO. This is entirely possible because the materials used to make binding metals are abundant in the Earth's crust. Vanadium sells for about $25/kg, and strontium is even cheaper.

"Our bonding metal works very well compared to ITO. The question now is how to scale up the material. With the current understanding, strontium vanadate could completely replace ITO in the same industrial equipment," says Engel-Herbert.

The team has filed a patent for the new technology and believes their material could also be used to develop cheap solar cells in the future.

According to VnExpress