California University Students Find Speed Of Tangled Transistor

Transistors are irreplaceable components in electronics today. Every device from a small gadget to a large computing machine uses a transistor in some way or the other. Latest are the reports of an unusual transistor which constitutes  many channels of Carbon nano-tube ink.  A group of students studying at University of California are optimistic of developing some innovative methods which would then be used to make flexible and printable devices  able to operate at low temperatures , which the plastic substrate can sustain, of course, not exceeding the extreme temperature for that plastic substance.


Transistor in study by University of California students

The transistor basically employs a tangle nature of carbon nano-tubes. Specifically this structure is very good in case of transportation of electrons as compared to our normal transistor. Caltech research students have been focusing on the difference the structure makes depending on the concentration of these carbon nano-tubes. So in a simple demonstration, by drying a sample of ink, the team discovered that the density of carbon nano-tubes does have an effect on working of the printing devices.

One of the key researchers in the team Nima Rouhi observed a wafer sample under an electron microscope only to find out the precise density which can be used to optimize the printing capability of the gadget. When the concentration of carbon nanotubes is around 100 per square micron, the difference in magnitude of current in transistor’s ON and OFF state was observed to be least. This was under the laboratory conditions. The team also found out some probable reasons of this phenomenon. Rouhi believes that perhaps it was because of presence of some stray metallic nanotubes in the semiconducting inks. The work of these metallic nanotubes is to serve as a connection between the source and the drain. So, more the number of these nanotubes, the efficient will be the performance of transistors.

A similar type of experiment was earlier conducted by Sunchon National University, South Korea; however they did not taken into account the concentration of nanotubes in improving the efficiency of these transistors. The South Korean university had reportedly made one bit flexible RFID tags with Carbon nanotubes.

The team has found out the electron mobility of its fastest device to be about 90cm²/Vs. The research study of the students has been published in Advanced Materials.

Source: IEEE