Electronic advances - the transparent transistor

Engineers at Oregon State University have created what is claimed to be the first transparent transistor, a see-through electronics component that could open the door to many new products.

The advance has been reported in the professional journal, Applied Physics Letters, and a patent has been applied for.

The university is already consulting with major electronics companies about the findings and their potential applications.

The discovery "is a significant development in the context of transparent electronics," the scientists said in their publication, but added that it's too early to tell what applications may evolve.

"This is a significant new advance in basic electronics and material science," said John Wager, a professor of electrical and computer engineering at OSU.

"There's no doubt it will open the door to some interesting new products businesses, but we're not sure what all they might be.

"It's a little bit like lasers when they were first developed in the 1960s - people at first thought they were an interesting novelty, but no one was quite sure what they could be used for," he said.

"Later on, lasers became the foundation of dozens of products and multibillion dollar industries. Right now we're just beginning to think about what you could do with a transistor you can see through."

The transparent transistor is made from a common compound that also happens to filter out ultraviolet light that many people might associate with preventing sunburn on their nose - zinc oxide.

But that's part of the strength of the new finding, researchers say. The basis of a potential new industry is a compound that's cheap, safe and easy to work with, a good electrical conductor, transparent, can be deposited in thin layers at low temperatures and is environmentally benign.

The findings are the result of several years of graduate research undertaken by Randy Hoffman, Ben Norris and other coworkers at OSU, which is developing one of the world's leading programs in transparent electronics.

The transistors might improve the quality of liquid crystal displays, which are a 10 to 15 billion dollar industry, making the displays more clear and bright.

Electronic devices might be built into window glass of the windscreen of a vehicle, allowing a range of new functions or the transmission of visual information.

Many electronic devices such as flat panel displays have glass that now serves no electronic purpose, but could accommodate new circuits or functions.

There should eventually be a range of applications in consumer electronics, transportation, business and even the military, Wager said.

Transparent materials that conduct electricity have been around since the 1940s, Wager said, and have found their way into many applications - flat panel displays, solar cells, car windscreens that can defrost themselves.

But the advent of transparent transistors, he said opens up the much broader potential of electronic devices that require control, logic, switching and other transistors functions that are essential to modern information systems.

The new transistors, Wager said, are 'n-type' semiconductors, which use basic electron transport and move quickly and efficiently compared to 'p-type' products.

The OSU research team is continuing its study of this and other compounds that could function as transparent transistors, and different device designs. The university is employing a multidisciplinary approach to this research using chemists, physicists and engineers, to help anticipate problems and also produce finding that could quickly be translated into useable products by private industry.