22. June 2022
New publi­ca­tion by Shu-Jen Wang
© Hector Fellow Academy

Paper by Shu-Jen Wang and Karl Leo published in the journal Nature

The inven­tion of the transis­tor in 1947 by Shock­ley, Bardeen and Brattain at Bell Labora­to­ries ushered in the age of micro­elec­tron­ics and revolu­tion­ized our lives. First, so-called bipolar transis­tors were invented, in which negative and positive charge carri­ers contribute to the current trans­port, unipo­lar field effect transis­tors were only added later. The increas­ing perfor­mance due to the scaling of silicon electron­ics in the nanome­ter range has immensely accel­er­ated the process­ing of data. However, this very rigid technol­ogy is less suitable for new types of flexi­ble electronic compo­nents, such as rollable TV displays or for medical appli­ca­tions on or even in the body.

For such appli­ca­tions, transis­tors made of organic, i.e. carbon-based semicon­duc­tors, have come into focus 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. Karl Leo and Dr. Hans Kleemann at the TU Dresden has now succeeded for the first time in demon­strat­ing an organic, highly efficient bipolar transis­tor. Crucial to this was the use of highly ordered thin organic layers. This new technol­ogy is many times faster than previ­ous organic transis­tors, and for the first time the compo­nents have reached operat­ing frequen­cies in the gigahertz range, i.e. more than a billion switch­ing opera­tions per second.

Dr. Shu-Jen Wang, Associ­ated Young Researcher in the Hector Fellow Academy, who co-led the project with Dr. Michael Sawatzki, explains: "The first realiza­tion of the organic bipolar transis­tor was a great challenge, since we had to create layers of very high quality and new struc­tures. However, the excel­lent parame­ters of the compo­nent reward these efforts!”

Congrat­u­la­tions Shu-Jen Wang and Karl Leo!