Transparent electronics is an emerging technology which aims to produce invisible electronic circuits. Now, researchers from Oregon report they made a major advance in transparent electronics. Their zinc-tin-oxide 'thin-film' materials are amorphous, physically robust, chemically stable and cheap to produce at just above room temperature. These new materials and transistors offer many new possibilities for consumer electronics, transportation, business and the military. Even if these transparent transistors don't show up inside your next computer, they might soon appear in flat panel screens, flexible electronics devices you'll carry with you, and even in your car windshields. But it should take some time. Read more.
Before going further, please remember that the following quotes are written in PR jargon. So read them with a grain of salt.
Researchers at Oregon State University (OSU) and Hewlett Packard have reported their first example of an entirely new class of materials which could be used to make transparent transistors that are inexpensive, stable, and environmentally benign. This could lead to new industries and a broad range of new consumer products, scientists say.
This is a significant breakthrough in the emerging field of transparent electronics, experts say. The new transistors are not only transparent, but they work extremely well and could have other advantages that will help them transcend carbon-based transistor materials, such as organics and polymers, that have been the focus of hundreds of millions of dollars of research around the world.
It's time for more 'technical' details about these zinc-tin-oxide thin film transistors.
They are amorphous, meaning they have no long range crystalline order, which helps to keep processing costs a great deal lower. They are also physically robust -- hard to scratch, chemically stable, resist etching, and have a very smooth surface. They are made from low cost, readily-available elements such as zinc and tin, which raise no environmental concerns.
"What has been most surprising, however, is that we can make high quality oxide transistors with these new materials at just above room temperature," said John Wager, a professor of electrical and computer engineering at OSU. "Simply put, that's shocking. Most integrated circuits made today, by comparison, are produced at temperatures between 700-1,100 degrees centigrade."
Standing on the bare ground,—my head bathed by the blithe air, and uplifted into infinite space,—all mean egotism vanishes. I become a transparent eye-ball; I am nothing; I see all; the currents of the Universal Being circulate through me; I am part and particle of God.
—Ralph Waldo Emerson (1803–1882)
Here is a photograph of a 1 inch by 1 inch glass substrate patterned with spin-coated zinc oxide transparent transistors, sitting on the top of a dollar bill. There are 56 transparent transistors present in the red box. Can you see them? Of course not, they're transparent. (Credit: Oregon State University)
As you probably guessed by now, this technology is a nascent one. But researchers are very optimistic about future uses, for example with gas sensor systems.
These sensors are used extensively in automotive and other mechanical applications, and the new zinc-tin oxide transistors might allow the creation of a new type of gas sensor whose sensitivity is electronically controlled over a wide dynamic range.
In the field of transparent applications, there should be uses in consumer electronics, transportation, business and the military. Automobile windshields could transmit visual information. Glass in almost any setting could also double as an electronic device, possibly improving security systems or transparent displays. The military is extremely interested in research of this type because of possible uses in sophisticated technology or fighting equipment.
For more information about transparent electronics, you should visit John Wager's home page at Oregon State's School of Electrical Engineering and Computer Science. Here is a direct link to his research activities.
The latest work done by Wager and his colleagues has been published online by Applied Physics Letters on December 23, 2004. Here is a link to the abstract of this paper named "High mobility transparent thin-film transistors with amorphous zinc tin oxide channel layer."
A previous paper about these see-through transistors was published last year by the Journal of Physics D: Applied Physics. Here is a link to this full paper, named "Spin-coated zinc oxide transparent transistors," from which the above illustration was extracted.
A symbol is indeed the only possible expression of some invisible essence, a transparent lamp about a spiritual flame; while allegory is one of many possible representations of an embodied thing, or familiar principle, and belongs to fancy and not to imagination: the one is a revelation, the other an amusement.
—William Butler Yeats (1865–1939)
Sources: Oregon State University news release, via EurekAlert!, December 28, 2004; Applied Physics Letters, Volume 86, Issue 1, January 3, 2005; Journal of Physics D: Applied Physics, Volume 36, Number 20, October 21, 2003; and various websites
Related stories can be found in the following categories.
Electronics
Future
Materials
Science.