Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Increasing Charge Mobility in Single Molecular Organic Crystals


Studies may help identify best materials for variety of future electronics applications

Flexible displays that can be folded up in your pocket? More accurate biological and chemical sensors? Biocompatible electronics? In research that may help determine the best materials for a wide range of future electronics applications, a scientist from the U.S. Department of Energy’s Brookhaven National Laboratory will report on the intrinsic electronic properties of molecular organic crystals at the March 2005 meeting of the American Physical Society. Brookhaven materials scientist Vladimir Butko will describe the experimental techniques and key findings on Monday, March 21, at 3:42 p.m. in room 152 of the Los Angeles Convention Center.

Organic materials are particularly attractive for potential applications such as flexible displays, or so-called “electronic paper,” because they are inherently flexible. “Imagine a computer screen that you could crumple or fold like a sheet of plastic film,” Butko says. Yet for this and any other electronics application, the materials must also be able to carry an electric current.

“These organic materials, by themselves, have almost no charge carriers — electrons or “holes” [the absence of electrons] — to carry current,” Butko says. “They act as insulators. But if we inject charge carriers, we can sometimes create organic devices such as field-effect transistors [FETs], through which charge will flow.”

To find out which materials have the best potential for carrying current, Butko has been studying single crystals of molecular organic materials such as pentacene and rubrene. Though these crystals themselves may not have direct applications, they provide the simplest form in which to study the materials’ intrinsic electronic properties — unaffected by factors that might play a role in larger samples such as polycrystalline thin films.

The key, says Butko, is to know whether the injected charge carriers will have a high mobility or stay localized. The most stringent test of localization is to cool such a device to very low temperatures: somewhat close to absolute zero, which is approximately -273 degrees Celsius. At these low temperatures the mobility edge can be probed without the complication of thermal activation -- a process that assists charge carrier transport in semiconductors due to large thermal energy at high temperatures. The studies were done using a physical properties measurement system (PPMS) and electrometers at the Los Alamos National Laboratory.

In his talk, Butko will present first evidence for low-temperature, quasi-temperature-independent transport of injected charge in a crystalline organic FET. “These materials, which also have the highest charge mobility at room temperature among organic FETs, can be most useful for electronic applications,” Butko says.

Once scientists identify the best crystals, they will use thin-film methods to test their applicability for electronic devices from e-paper to large-format display screens.

This research was done in collaboration with Arthur Ramirez, David Lang and Xiaoliu Chi from Bell Laboratories, and Jason Lashley from Los Alamos National Laboratory, and was funded in part by the Office of Basic Energy Sciences within the U.S. Department of Energy’s Office of Science.

Karen McNulty Walsh | EurekAlert!
Further information:

More articles from Materials Sciences:

nachricht From ancient fossils to future cars
21.10.2016 | University of California - Riverside

nachricht Study explains strength gap between graphene, carbon fiber
20.10.2016 | Rice University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>