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Andreas Ullmann
Researcher at Siemens
Publications - 108
Citations - 1073
Andreas Ullmann is an academic researcher from Siemens. The author has contributed to research in topics: Layer (electronics) & Organic field-effect transistor. The author has an hindex of 14, co-authored 108 publications receiving 1069 citations.
Papers
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Journal ArticleDOI
Fast polymer integrated circuits
TL;DR: Using soluble polymers for the active layer and insulating layer, a concept for the fabrication of fast integrated circuits based on p-type organic transistors only is reported in this paper, where ring oscillators with frequencies above 100 kHz and propagation stage delays below 0.7 μs are presented.
Journal ArticleDOI
From polymer transistors toward printed electronics
TL;DR: In this paper, the authors present results on high performance polymer transistors, mainly based on poly-3alkylthiophene (P3AT) as semiconducting material.
Journal ArticleDOI
Stability of polythiophene-based transistors and circuits
TL;DR: In this paper, a detailed investigation on shelf life and operation lifetime of polymer field effect transistors (PFETs) and circuits is reported, all examined devices consisted entirely of polymer materials except the electrodes.
Journal ArticleDOI
High Performance Organic Field-Effect Transistors and Integrated Inverters
Andreas Ullmann,Jürgen Ficker,Walter Fix,Henning Rost,Wolfgang Clemens,Iain McCulloch,Mark Giles +6 more
TL;DR: In this article, the authors presented the fabrication of organic field effect transistors (OFETs) and integrated inverters using polymer semiconductors and insulators, and they obtained a mobility of 0.2cm2/Vs for poly(3-alkylthiophene) and poly(4-hydroxystyrene) (PHS) respectively.
Proceedings ArticleDOI
Fast Polymer Integrated Circuits Based on a Polyfluorene Derivative
Walter Fix,Andreas Ullmann,Jürgen Ficker,Henning Rost,Wolfgang Clemens,D. Brennan,D. Welsh,J. O'Brien +7 more
TL;DR: In this article, a novel concept based on p-type organic transistors only is reported, where a poly(fluorene bithiophene) derivative is used as active semiconducting layer, a copolymer blend as insulator, a flexible polyester film as substrate and metal electrodes.