System Bits: Jan. 14

Fastest organic transistor
Research teams from the University of Nebraska-Lincoln and Stanford University have worked together to produce what they believe are the world’s fastest thin-film organic transistors, proving that this experimental technology has the potential to achieve the performance needed for high-resolution television screens and similar electronic devices. The researchers said the transistors could operate more than five times faster than previous examples of this experimental technology.

For years engineers have tried to use inexpensive, carbon-rich molecules and plastics to create organic semiconductors capable of performing electronic operations at something approaching the speed of costlier technologies based on silicon. The term “organic” was originally confined to compounds produced by living organisms but now extended to include synthetic substances based on carbons and includes plastics.

Now, the research teams have used their new process to make organic thin-film transistors with electronic characteristics comparable to those found in expensive, curved-screen television displays based on a form of silicon technology and achieved their speed boost by altering the basic process for making thin-film organic transistors.

To make them, normally a special solution containing carbon-rich molecules and a complementary plastic is dropped onto a spinning platter – such as glass – that deposits a thin coating of the materials over the platter.

In this work, the researchers spun the platter faster and only coated a tiny portion of the spinning surface, equivalent to the size of a postage stamp. These changes had the effect of depositing a denser concentration of the organic molecules into a more regular alignment which greatly improved carrier mobility which measures how quickly electrical charges travel through the transistor.

While this off-center spin coating process remains experimental, and the engineers cannot yet precisely control the alignment of organic materials in their transistors or achieve uniform carrier mobility, the process produced transistors with a range of speeds much faster than those of previous organic semiconductors and comparable to the performance of the polysilicon materials used in today’s high-end electronics.

Transparent transistors on this postage-stamp size glass have speed characteristics rivaling some forms of silicon transistors. The device used a new process to make this world record-setting organic transistor, paving the way for a new generation of cheap, transparent electronic devices. (Source: Stanford University)

 
The researchers believe further improvements to this process could lead to the development of inexpensive, high-performance electronics built on transparent substrates such as glass and, eventually, clear and flexible plastics.

Quantum physics’ two sides
An ETH Zurich professor pointed out that the decryption of secret information using quantum physics is currently causing a stir in the media but that not enough attention is paid to the fact that quantum physics is also revolutionizing the encryption of data.

In regard to the security of secret information, quantum physics is particularly important, according to Renato Renner, Professor at the Institute for Theoretical Physics at ETH Zurich. First, he said, it is possible that it will be relatively easy in future to crack today’s encryption systems with quantum computers. Recently, citing documents from Edward Snowden, the Washington Post reported that the NSA is pursuing a research program to build quantum computers. However, experts agree this is a long-term goal that will not be implemented for at least another 20 years. Second, quantum physics and the field of quantum cryptography are creating new possibilities for the secure encryption of data, and initial applications already exist in this area. This is also of interest to the NSA.