Printed SmartCards and Internet-of-Things with Quantum Functional Circuit Elements using Conjugated Polymers, Paul R. Berger

Also see Organic Conducting Polymer Flexible Electronics and Foldable Displays and Photovoltaics


Advisor: Paul R. Berger

Conner Chambers (ECE Masters)
Petri Heljo (Visiting PhD candidate from Tempere University of Technology, Finland)
Ms. Sarah AL-Issa (ECE undergrad researcher to Masters)

Former Graduate Students:
Woo-Jun Yoon (ECE Master's thesis 2006, Ph.D. 2009)
Ms. Sita Asar (Physics undergrad researcher)

Prof. Donald Lupo (Tempere University of Technology, Finland)

Importance of the Problem:

This project examines quantum functional devices in the conjugated polymer system for molecular electronic devices and circuits. These enhanced circuits are aimed to be more energy thrifty than conevtional transistor-only circuits and facilitate high-speed operation to reach node-to-node iwireless communication.

Brief Description of Our Work and Results:

Conjugated polymers, with pi molecular orbitals delocalized along the polymer chain, are useful organic semiconductors that provide the possibility of molecular electronics for low power organic-based memory and logic. Quantum functional devices based upon carrier tunneling processes open vistas into very efficient and low power consumption circuitry that would be ideal for these applications.

We demonstrate here strong room temperature NDR for poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylenevinylene] (MEH-PPV) polymer tunnel diodes using a thin TiO2 tunneling layer (~2-8 nm) sandwiched between the MEH-PPV and the indium tin oxide anode.

A key advantage is the pronounced NDR using a thick polymer layer with a large active area, circumnavigating the need for molecularly sized junctions. Current-voltage measurements show large and reproducible NDR with a PVCR as high as 53 at room temperature. We also demonstrate basic logic circuit operation using a pair of these polymer tunnel diodes connected in series to form a monostable-bistable transition logic element latch. Our results indicate that polymer tunnel diodes are potential candidates for many flexible, low-power logic and memory applications for organic devices by using low-cost and simple solution processing.

Awards, Citations and Recognitions

Electronics News: "Organic Polymer Builds Tunnel Diode" (November 22, 2005)

Active and Intelligent Pack News: "Organic polymer diode could lead to cheaper RFID" (December 2005);

Wafer News: "Exploring polymer tunnel diodes to enable logic functions" (January 2006);

Science and Vie (France's Scientific American): "Plastic diodes promise low cost memory" (July 2006).


  1. "Demonstration of Room Temperature Negative Differential Resistance in Polymer Diodes Using a Thin Oxide Tunneling Barrier at the Anode," Paul R. Berger and Woo-Jun Yoon, [Disclosure submitted May 17, 2005; provisional filed November 3, 2005, full patent filed November 3, 2006, Serial. No. & Code 11/592,419].


Manufacturable NDR Devices and Processes

  1. Anodic Oxidation of Ultra-Thin Ti Layers on ITO Substrates and their Application in Organic Electronic Memory Elements," Petri Heljo, Karsten Wolff, Kimmo Lahtonen, Mika Valden, Paul R. Berger, Himadri Majumdar, and Donald Lupo, Electrochimica Acta, vol. 137, pp. 91-98 (2014).

Large Room Temperature Negative Differential Resistance

  1. "Room Temperature Negative Differential Resistance in Polymer Tunnel Diodes using a Thin Oxide Layer at the Anode and Demonstration of Threshold Logic," Woo-Jun Yoon, Sung-Yong Chung, Paul R. Berger, and Sita M. Asar, Applied Physics Letters, 87, 203506 (November 14, 2005). PDF (173 kB)

Invited Talks

  1. "Next generation plastic low cost memory devices," Paul R. Berger, NanoElectronics: Near Term Commercial Applications for Nanotechnology in Electronics, San Jose, California, (November 8-10, 2006). Conference brochure/agenda (PDF)

Conference Presentations

  1. "Fabrication and defect properties of ultra-thin TiO2 interfacial layers for hybrid tunnel diodes," P. Heinonen, C. Chambers, P. S. Heljo, P. R. Berger, and D. Lupo, to be presented at the 2014 Fall MRS Meeting (Boston, MA, November 30 to December 5, 2014).

  2. "Resonant Tunneling and Room Temperature Negative Differential Resistance in TiO2/MEH-PPV Junctions for Quantum Functional Circuits, Woo-Jun Yoon, Andrew P. Bonifas, Richard L. McCreery, and Paul R. Berger, OSA's Organic Photonics and Electronics (OPE) Topical Meeting at Rochester, NY, (October 9-11, 2006).

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Last updated October 21, 2014.

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