Newswise — Amorphous silicon has long been the king of flat-panel displays, but soon its dominion will pass, because this material can't provide the speed and stability that next-generation TVs and computer monitors will require. Those displays will have to refresh their pixels two to four times as rapidly as today's versions; the three-dimensional displays will have to be twice again as fast as that.
Researchers and display manufacturers already have their eyes set on a promising heir--in fact, a whole family of materials, known as amorphous oxide semiconductors. They're amorphous because, like today's silicon standby, they lack a regular crystalline structure, and they're oxides because they're made of oxygen compounded with two or three metals.
Amorphous oxides can form thin films that are transparent and electrically conductive, which is why they already serve as the see-through electrode layer in displays and solar cells. But amorphous oxides could also replace amorphous silicon as the active semiconducting material that does the heavy lifting as the channel in thin-film transistors.
Here's what's great about amorphous oxides: First and foremost, charge can zip through them 20 to 40 times as fast as in amorphous silicon. Second, unlike amorphous silicon, amorphous oxides can be deposited at low temperatures, which means they can be laid down or even printed on pliable plastic sheets to make paperlike displays. Finally, because the materials are transparent, they could be used in electronic-ink screens that could be laminated on windshields, windows, and eyeglasses.
A more ambitious goal would be to fashion these materials into transistors rather like complementary metal-oxide semiconductor (CMOS) technology. Such devices would juggle not only electrons but also "holes," positively charged virtual particles, making possible low-power electronic chips. To get to that goal, though, researchers must first discover a hole-producing, "p-type" form of amorphous oxides.
These materials are still in their early adolescence; practical work started only about five years ago. In a few more years, they'll start appearing in your home, in your hand, and perhaps even on the lenses of your glasses.
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