Transparent Transistors Made from Nanowires

Organic light has fascinated mankind for centuries and the quest to replicate nature's engineering abilities has preoccupied many scientists. An organic light-emitting diode (OLED) is any light-emitting diode (LED) whose emissive electroluminescent layer comprises a film of organic compounds.

The layer usually contains a polymer substance that allows suitable organic compounds to be deposited. They are deposited in rows and columns onto a flat carrier by a simple "printing" process. The resulting matrix of pixels can emit light of different colors.

OLEDs contain transistors, semiconductor devices, commonly used as amplifiers or as electrically controlled switches. The transistor is the fundamental building block of the circuitry that governs the operation of computers, cellular phones and all other modern electronics.

Researchers at Purdue University and Northwestern University have now made flexible, see-through transistors using zinc-oxide and indium-oxide nanowires, that perform even better than their silicon counterparts and are easier to fabricate on flexible plastic.

Flexible electronics - also known as flex circuits or flex circuit boards - represent a technology for building electronic circuits by depositing electronic devices on flexible substrates such as plastic or even organic materials.

David Janes led the team that created the transparent transistors, and said that "you could put transparent transistors underneath or on top of the pixel," thus increasing the light-emitting area and the overall performance.

The practical applications of this new technology would have a great impact in the field and could lead the way to producing brighter, transparent OLED displays. These could be used to produce maps on visors and windshields, or television screens built into eyeglasses and roll-up, see-through computer screens.

OLEDs can also be used in light sources for general space illumination and large area light-emitting elements, or on clothing which displays electronic messages, or even in packaging for common goods that could be made to display electronic messages such as health warnings and recipes, or could emit light.