Organic bipolar transistor developed at Tu Dresden
Professor Karl Leo has been thinking about realizing this component for more than 20 years, now it has become reality: His research group at the Institute for Applied Physics of TU Dresden has presented the first high-efficiency organic bipolar transistor. This opens up entirely new perspectives for organic electronics, both in data processing and transmission and in medical technology applications.
The invention of the transistor in 1947 by Shockley, Bardeen and Brattain at Bell Laboratories ushered in the era of microelectronics and revolutionized our lives. First, so-called bipolar transistors were invented, in which negative and positive charge carriers contribute to current transport, and unipolar field-effect transistors were added later. The increase in performance due to the scaling of silicon electronics into the nanometer range has dramatically accelerated data processing. However, this very rigid technology is less suitable for new types of flexible electronic components, such as rollable television screens or for medical applications on or in the body.
For such applications, transistors made of organic semiconductors – carbon-based – have received particular attention in recent years. Organic field effect transistors were introduced as early as 1986, but their performance still lags far behind silicon components.
A research group led by Prof. Leo and Dr. Hans Kleemann at TU Dresden has now succeeded in demonstrating a highly efficient organic bipolar transistor. The use of highly ordered thin organic layers was crucial for this. This new technology is many times faster than previous organic transistors, and the components have reached gigahertz operating frequencies, or more than a billion switching operations per second. Dr Shu-Jen Wang, who co-led the project with Dr Michael Sawatzki, explained: “The first realization of the organic bipolar transistor was a big challenge, because we had to create very high quality layers and new structures. . However, the excellent component parameters reward these efforts!” Professor Leo added: “We have been thinking about this device for 20 years and I am delighted that we have been able to demonstrate it with the new highly ordered layers. The organic bipolar transistor and its potential open completely new perspectives for organic electronics. because they also enable demanding tasks in data processing and transmission.Possible future applications are, for example, smart patches equipped with sensors that process sensor data locally and communicate wirelessly with the outside.