Molecular Electronics 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 Students: Woo-Jun Yoon (ECE Ph.D. candidate)

Importance of the Problem:

This project examines quantum functional devices in the conjugated polymer system for molecular electronic devices and circuits.

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).

Patents

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].

Publications

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

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 2, 2007.

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