By Mark Halper
Posting in Energy
Thin film oxides could handle more heat and power than silicon can, supporting higher voltage smart grids, expanding the reach of sensors, and pushing the frontiers of electronics.
Our lives depend on silicon-based electronics. Semiconductors built from the sand-based material pervade our gadgets, computers, cars, vending machines, stop lights, toys, games, road signs, bank cards, you name it.
But for all its ubiquity, silicon has its limitations. For one: it can only handle so much power and heat.
Researchers at North Carolina State University have taken a big step toward an alternative material - a thin film oxide - that would withstand more extreme conditions than silicon, auguring improvements in everything from high voltage electricity transmission to sensors operating in high temperature environments.
"Because oxides can handle higher voltages than silicon-based electronics, the material could be used to create higher voltage switches for the power grid, which would allow more power to be transmitted on the existing infrastructure," writes the website Physorg. "Similarly, this would allow the develpment of sensors for use in higher-temerature enviornments, because oxides are more stable at high temperatures."
The material also portends new types of gas sensors, including testing for air toxicity in security situations, the article states.
Scientists have known about the potential for thin film oxides for some time. But the NC State team has cracked a major obstacle: It has figured out how to make an efficient junction between the "positive" and "negative" regions.
To overcome the nagging inefficiency that has plagued earlier attempts at deploying thin film oxides, the researchers used the same material for both the positive and negative side. It created nickel oxide thin film for the positive side, and then converted the same material to a negative type, by using lasers.
"This is a new era in oxide electronics," says Jay Narayan, the John C. Fan Distinguished Chair Professor of Materials Science and Engineering, as quoted by Physorg.
As an added benefit, Narayan points out that "these materials are also transparent, so this makes transparent electronics possible," (perhaps supporting see through photovoltaic windows?).
Narayan is one of the co-authors of a paper, "Controlled p-type and n-type conductivity transformation in NiO thin films by ultraviolet-laser irradiation," published in the Journal of Applied Physics.
Photo from Jon Sullivan via Wikimedia Commons
More material developments on SmartPlanet:
- See-through solar window creator invents invisible wires
- Graphene the Sequel: Graphyne. It's flashier.
Mar 25, 2012
Oxides have a lot of competition from more semiconductors than silicon. Even silicon still demonstrates some incredible capabilities. The Navy has demonstrated multi-megawatt power switching with a type of silicon diode. Silicon carbide just gets going at about 300degC. The whole class of wide bandgap semiconductors operate comfortably at high temperatures. My pet peeve is labs, who have a nice little demonstration, who hype it into a "new era". "In God we trust, everyone else must bring data."
Nice thought brianalls, but I don't think this would affect the need for rare earths one way or another. Anyone else know differently?
Impressionist - you're correct. Go to the head of the class. Hoodedswan- in the absence of a literal photo of nickel oxide thin film, I decided to go with an image conveying "extreme" and "heat," and to leave out the caption. Thus, the cropped picture of ground display explosions from the Miramar Air Show in San Diego. Hot stuff, but I can see how the symbolism might have been lost in this particular photo, and how the photo might even have hinted at the oxide manufacturing process. The photo has nothing to do with the making of thin film oxides. Perhaps if I hadn't cropped it, that would have been more clear. The original version at http://commons.wikimedia.org/wiki/File:Explosions_at_Miramar_Airshow.jpg shows a military tank. Now, I know that many technologies start out in the military lab, but we're all in trouble if we need armored fighting vehicles to manufacture our next generation of electronic chips! Sorry for the confusion, and thanks for the feedback.