Organic light-emitting diode (OLED) displays are currently found on mobile phones and digital cameras. But in the future, manufacturers expect bigger, bendable, and completely transparent versions. They envision bright maps on visors and windshields, television screens built into eyeglasses, and roll-up, see-through computer screens.
And although the OLEDs themselves can be transparent, to make a clear display, the transistors that control each display’s OLED, or pixel, need to be transparent as well. Recently, researchers from Hanyang University in Seoul constructed a thin film transistor made of networked single-walled carbon nanotubes (SWNTs) on a glass substrate.
While this is not the first thin film transistor made of SWNTs, it has the advantage of allowing a high density of SWNTs to be grown under lower temperatures than normally required.
This method undertaken by the researcher shows that nanotubes can offer a practical choice for fabricating transparent, thin film electronics such as flat-panel displays and future opto-electronics devices.
Researchers explained how the SWNT network can be arranged through a technique called chemical vapor deposition. In this method, the substrate is pre-patterned with catalysts to prevent the need for etching, and the nanotubes can be directly deposited on the substrate. By enhancing this technique with the use of a water plasma, the scientists were able to grow the nanotubes at significantly lower temperatures than in previous methods.
This quest for flexible and transparent transistors has recently resulted in several noteworthy achievements. Transparent transistors have been fabricated using both polymers and inorganic oxides. These advances, notable in the emerging technology arena that is generally called ‘plastic electronics’, have received wide publicity. Both, nevertheless, have significant deficiencies. The former have low mobility and the latter do not have the desired flexibility and are not easily manufacturable. These factors severely limit the application potential of the devices. Our method introduces a transistor architecture that potentially includes only two materials: carbon nanotubes (NTs) and a polymeric gate insulator. This simplicity of structure would ensure a simple manufacturing process.
In the future, the scientists plan to make improvements to the nanotube transistors by increasing their mobility and further understanding the complex configuration of the nanotube networks.
Via: Physorg
