► High-speed flexible transistors and tunnel diodes and circuits based on them


Professor Dr. Thomas Riedl

Bergische Universität Wuppertal
Fakultät für Elektrotechnik, Informationstechnik und Medientechnik
Lehrstuhl für Elektronische Bauelemente

Professor Dr. Ullrich Scherf

Bergische Universität Wuppertal
Fakultät für Mathematik und Naturwissenschaften
Arbeitsgruppe Makromolekulare Chemie                                                   

Project Summary

The aim of this proposal is the development of novel high-speed electronic devices for integration into flexible substrates made in scalable processes that are suitable as components of circuits for high-speed wireless communication through the following activities: Synthesis: The synthesis part is focused on (high mobility) semiconducting polymers. Several classes of materials with a favorable energy level alignment will be tested. Promising materials will be optimized in terms of solubility and processing conditions for application in tunnel diodes and TFTs.TFT: For a few promising materials high-speed p-channel organic TFT devices (typ. 1 µm) with self-aligned lithographically patterned D/S electrodes for lowered parasitic capacities will be prepared and characterized for their high-frequency characteristics. Complementary, high-speed n-channel metal-oxide based TFTs in planar device geometry will be developed. To overcome geometrical limitations of the planar device layout, short channel metal-oxide based vertical TFTs will be prepared using the specific benefits of atomic layer deposition for the preparation of electrodes, dielectrics and channel material. Based on this concept, we expect to push ft into the region > 2 GHz. Design and realization of amplifier circuits based on high-speed TFTs is another topic in this proposal.Tunnel diodes: Topic of this part is the fabrication and optimization of organic tunnel diodes with a view to implementation in high-speed voltage-controlled oscillators. Key performance targets in the selection of suitable polymeric semiconductors are high peak to valley ratio, oscillation > 1 GHz, onset of NDR at low V and maximized output current.Oscillator: This part is focused on the development of a voltage-controlled oscillator based on a flexible organic tunnel diode in the GHz range. The individual building blocks will be married for the design and realization of a RF transmission circuit.