Nav: Home

Organic semiconductors: One transistor for all purposes

March 21, 2019

In mobiles, fridges, planes - transistors are everywhere. But they often operate only within a restricted current range. Ludwig-Maximilians-Universitaet (LMU) in Munich physicists have now developed an organic transistor that functions perfectly under both low and high currents.

Transistors are semiconductor devices that control voltage and currents in electrical circuits. To reduce economic and environmental costs, electronic devices must become smaller and more effective. This applies above all to transistors. In the field of inorganic semiconductors, dimensions below 100 nanometers are already standard. In this respect, organic semiconductors have not been able to keep up. In addition, their performance with regard to charge-carrier transport is considerably worse. But organic structures offer other advantages. They can easily be printed on an industrial scale, the material costs are lower, and they can be transparently applied to flexible surfaces.

Thomas Weitz, a professor in LMU's Faculty of Physics and a member of the Nanosystems Initiative Munich, and his team are working intensively on the optimization of organic transistors. In their latest publication in Nature Nanotechnology, they describe the fabrication of transistors with an unusual structure, which are tiny, powerful and above all versatile. By carefully tailoring a small set of parameters during the production process, they have been able to design nanoscale devices for high or low current densities. The primary innovation lies in the use of an atypical geometry, which also facilitates assembly of the nanoscopic transistors.

"Our aim was to develop a transistor design which combines the ability to drive high currents that is typical of classical transistors with the low-voltage operation required for use as artificial synapses," says Weitz. With the successful assembly and characterization of vertical organic field-effect transistors with exactly selectable dimensions and an ionic gating, this goal has now been achieved.

Potential areas of application for the new devices include OLEDs and sensors where low voltages, high ON-state current densities or large transconductances are required. Of special interest is their possible use in so-called memristive elements. "Memristors can be thought of as artificial neurons, as they can be used to model the behavior of neurons when processing electrical signals," explains Weitz. "By fine-tuning the geometry of a memristive device, it could be applied in a variety of contexts, such as learning processes in artificial synapses." The researchers have already submitted a patent application for the device to enable them to develop the new transistor architecture for industrial use.
-end-


Ludwig-Maximilians-Universität München

Related Neurons Articles:

How do we get so many different types of neurons in our brain?
SMU (Southern Methodist University) researchers have discovered another layer of complexity in gene expression, which could help explain how we're able to have so many billions of neurons in our brain.
These neurons affect how much you do, or don't, want to eat
University of Arizona researchers have identified a network of neurons that coordinate with other brain regions to influence eating behaviors.
Mood neurons mature during adolescence
Researchers have discovered a mysterious group of neurons in the amygdala -- a key center for emotional processing in the brain -- that stay in an immature, prenatal developmental state throughout childhood.
Astrocytes protect neurons from toxic buildup
Neurons off-load toxic by-products to astrocytes, which process and recycle them.
Connecting neurons in the brain
Leuven researchers uncover new mechanisms of brain development that determine when, where and how strongly distinct brain cells interconnect.
The salt-craving neurons
Pass the potato chips, please! New research discovers neural circuits that regulate craving and satiation for salty tastes.
When neurons are out of shape, antidepressants may not work
Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed medication for major depressive disorder (MDD), yet scientists still do not understand why the treatment does not work in nearly thirty percent of patients with MDD.
Losing neurons can sometimes not be that bad
Current thinking about Alzheimer's disease is that neuronal cell death in the brain is to blame for the cognitive havoc caused by the disease.
Neurons that fire together, don't always wire together
As the adage goes 'neurons that fire together, wire together,' but a new paper published today in Neuron demonstrates that, in addition to response similarity, projection target also constrains local connectivity.
Scientists accidentally reprogram mature mouse GABA neurons into dopaminergic-like neurons
Attempting to make dopamine-producing neurons out of glial cells in mouse brains, a group of researchers instead converted mature inhibitory neurons into dopaminergic cells.
More Neurons News and Neurons Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.